XXHighEnd

Ultimate Audio Playback => XXHighEnd PC => Topic started by: acg on October 01, 2013, 06:19:21 am



Title: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 01, 2013, 06:19:21 am
Hi All,

Over the coming weeks I intend investigating the effect of providing linear power to various parts of the XXHE PC and any associated changes in sound quality.

I plan for this experimentation to be methodical rather than haphazard but I am forced to approach this from a beginners perspective, rather than the perspective of someone that has electronic experience or even power supply experience.  So I propose is to break up the investigation into a number of parts:
  • Define points of interest i.e. SATA, P24, P8, Fans, Peripherals
  • Measure amperage requirements of points of interest.  Best to do this while the XXHE PC is in use
  • Feed these individual points of interest with clean linear power and attempt to quantify any resulting changes to sound quality
  • Determine which points of interest are worth providing linear power
  • If feasible, design and build a high quality purpose built linear supply for the XXHE PC

So, first we figure out what to look at in regards of linear power and then we measure amperage draw, supply cheap linear power, make a judgement call, and then design a suitable supply if deemed appropriate.

To do this, I have invested in a relatively cheap, but decent quality 3 rail linear psu (http://www.ebay.com.au/itm/260686424661?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649).  I have heard this psu in action in another system where the owner claims a very worthwhile 10% improvement in sound quality (whatever that really means), but of course how this translates to an XXHE/NOS1 arrangement is anybody's guess.  For what it is worth, ItemAudio in the UK also recommend this unit as their pick of the lab psu's that they have tried.

In the coming days and weeks I plan to measure the draw of all the points of interest that I can and publish the results in this thread.  It would be ideal if I could convince others to duplicate this approach (or another approach that can be agreed upon).  Hopefully this can become a group effort with corroborated results in different systems and different countries with an aim to really figuring out if a linear psu for the XXHE PC is a viable or worthwhile endeavour.

For the initial measuring tasks, all that is needed is a multimeter, a screwdriver, some extension cables for whatever we are to measure the amperage draw, and some time to spare.  I would guess that different computers will have different power draws at different points of interest, so the more people that spend some time measuring this stuff the better.

Within my own XXHE PC I have identified four points of interest: the P8 EPS 12 V plug; the P24 ATX plug; the Pang USB Card Molex Connector; the SATA power cable for the Samsung 840 EVO SSD.  The most complex and difficult of these is going to be the P24 ATX plug, but if we approach this in a methodical way I am sure that we can achieve the best outcome.  I have prepared a pinout of these four points of interest in my XXHE PC...
 
Another point of interest will be powering the RAM directly, which is a much more difficult task.  People such as I that use a RAMdisk for playback may get good benefit from clean linear power at this location, but I really think we should leave this until last because it involves modifications to the motherboard.

Other potential points of interest for linear power include multiple internal SSD and/or HDD and even external drives.  I do not use these things myself, so someone else is going to have to measure them and determine if they should be powered individually, as a group, or at all.

So please put up your hands and even if you cannot do these measurements yourself, feel free to make suggestions.  When my gear turns up in the coming days I will post some pictures of how to measure these things for yourself, it is quite easy.

Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: pedal on October 01, 2013, 07:49:48 am
Wow, Anthony, this is a GREAT project by you. And I think your efforts will be rewarded. Power supply is "everything" in Hi-Fi and the general consensus is that cheap switching PSUs are bad in most (any?) stereo component.

I will follow this thread with great interest!


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 01, 2013, 09:56:54 am
Great stuff Anthony.

One remark in advance of things : I would never save myself a 200 on a supply which may have a 10x worse ripple etc. then the SPSU in there right now, if that would make a difference in the first place (which I don't know).
So be careful please that you may be able to get all running all right, but that next the quality is not on par at all, and you thus won't know what you are listening to. This, while I think you are doing this for the better, right ?
But of course, if you are only doing this as a cheap trial just to see whether you can get it running, then it's okay !

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 01, 2013, 10:22:55 am
Thanks Peter,

The ripple on that supply is 1mV rms, so it is pretty good, but I don't know how well designed the supply is and how much hash it feeds back into the mains.  Yes, the $200 psu is a cheap trial just to see if I can notice differences with it.  The aim is to figure out what, if anything, works and then use what we have measured and heard to possibly design and build a specialised unit for the XXHE PC.

Is it an easy endeavour to figure out how much hash this linear psu feeds back into the mains?  Are you able to give me instructions?  I probably should get that out of the way first.

Pedal, thanks also for the encouragement.  I hope we find a way to further improve the XXHE/NOS1 sound!

Regards,

Anthony

EDIT:  Peter, I had considered going the super high-quality route from the start and using Hynes regs and good quality transformers, but the cost is prohibitive once the rails add up and I really don't know how many rails I will need in the end.  It could be one, or zero, or six.  Who knows?  At $200 a pop for each Hynes reg that is a lot of money to spend on a hunch.
 


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 01, 2013, 12:16:25 pm
Assuming you have a scope, just hook that up to your 230V, let it show the sine which should be there and compare with PC On and Off.

A bit careful (with the Voltage too :)) because you maybe see so much rubbish in the first place that comparing is difficult. On the other hand, when this is so (much rubbish to start off with) it isn't going to help you much from that (mains) side either. But *that* does not count for everyone.
The other way around just the same : when yours is clean you may achieve results (because the SPSU is not clean at all), while I will not because I have the rubbish in the first place.

Isn't there then anything which is easy ?
:swoon:
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 01, 2013, 01:20:13 pm
Thanks Peter.  I don't have a scope but I know someone who probably does.  When the LPSU arrives I will take it and my XXHE pc around to him and see how they compare.  

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 01, 2013, 01:42:26 pm
Anthony,

Uhm ... You can do that of course, but maybe it is better to bring the scope to your place and in the mean time see how your mains behaves ...
Later you will be confronted with that anyway.

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: AlainGr on October 07, 2013, 01:25:23 pm
It is probable that many have seen this, but anyway...

http://www.teradak.com/en/product_view.asp?ID=214

contact: teradak@teradak.com

Seen on CA: http://www.computeraudiophile.com/f10-music-servers/teradak-computer-linear-power-supply-17689/#post260016

Alain


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: juanpmar on October 07, 2013, 05:10:23 pm
Alain, thanks for the link, it looks interesting. Have you contacted with TeraDak?

Br
Juan


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: AlainGr on October 07, 2013, 06:21:35 pm
Hi Juan,

Not really... I only conveyed the information that was on CA...

Regards,

Alain 



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 08, 2013, 12:41:25 am
It is probable that many have seen this, but anyway...

http://www.teradak.com/en/product_view.asp?ID=214

contact: teradak@teradak.com

Seen on CA: http://www.computeraudiophile.com/f10-music-servers/teradak-computer-linear-power-supply-17689/#post260016

Alain

Yes, I had seen that Alain and it is interesting.  The current on rails 1 - 3 seem very excessive and rails 4 and 5 will likely be no use (apparently -12v is seldom used these days).   To me the product looks like something that may not have received a lot of testing.

On another point, my three rail linear lab psu has arrived this morning and I am working on getting a suitable oscilloscope as well.  My plan is to measure and get a good idea of what the current situation is with my mains power and XXHE PC (ripple, noise etc.) and then measure the differences when using linear power.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 09, 2013, 03:00:45 am
Current draw for the P8 CPU Mobo Socket

Today I had a few minutes and decided to measure the current draw from the P8 CPU Socket on the Asrock X79 Extreme4-M motherboard and the Xeon E5-2648L 8 Core cpu.  This is not the standard cpu for the XXHE PC: it is a lower powered (1.80gHz) server cpu with more cores (8 physical) and more cache (20M).  As per Peters earlier advice I measured the current draw in both minimised o/s and non-minimised o/s modes; the results are below.

o/s Mode      Computer Startup      System Idle      Playing Music      Alt-X      Computer Shutdown
NOT-Minimised      3.78A1.15A3.3A--4.85A
Minimised3.78A0.9A1.2A1.64A2.62A

I find these results very interesting.  The CPU draws much less current at shutdown and when playing music if the o/s is not minimised, and a little more at idle when the o/s is not minimised.  Startup current draw seemed to be the same whether the o/s was minimised or not.

What was super interesting was how the current draw of the cpu was impacted by the minimised o/s.  Before minimisation, the cpu voltage was a constant rollercoaster ride that had ran as low as about 1.2A but cycled rhythmically to 2.5A and even 3.3A occasionally, but there was definitely a cycle happening where the current would ebb and flow.  In minimised o/s mode, the cpu was much, much more stable and operated in an amperage range of 1.05A to 1.2A with no real rhythm apparent.  That is a swing range of 0.15A compared to 2.1A which in the context of things is a very big difference.

Is there anybody out there that can duplicate this testing with the Asrock X79 Xtreme4-M mobo and the i7-3930K cpu?  Not only would the difference between processors be interesting, but the information is valuable should a linear psu prove worthwhile.  I will write another post shortly to summarize how to measure the power draw at this socket.

Anthony






Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 09, 2013, 03:38:39 am
#1 of 2 ways to measure the current draw at the P8 CPU Socket on the Mobo

If you have a lab supply that displays the voltage and current draw, this is very easy.

STEP 1 - Make a loom for the P8 socket.  I purchased a 8 pin EPS extension cable (such as this (http://www.ebay.com.au/itm/male-to-female-8-Pin-ATX-12V-CPU-EPS-P4-Power-Extension-connectors-Cable-TR-/400551972300?pt=AU_CablesConnectors&hash=item5d42c20dcc)) and cut one end off it (the end that does NOT plug into the mobo), twisted all the positive wires together and fed them into a banana plug, then twisted all the negative wires together and fed them into a different banana plug.  If you already had the 8 pin EPS plug and pins you could make up a cable yourself in about 5 minutes.  Apparently you can also feed the 8 pin P8 socket with a 4 pin P4 connector: you simply install it in the half of the 8 pin socket that is nearest the edge of the mobo.

STEP 2 - Turn on the lab psu and set the rail you are going to use to 12V and plenty of amps (minimum 5A, preferable 8A+)

STEP 3 - Remove the existing psu plug from the P8 socket on the motherboard and replace it with the new cable.  Plug the new cable into the 12V rail on the lab PSU.

STEP 4 - Turn on the lab psu.  You are now using two psu's for your motherboard.  For the computer to start the P8 cpu socket must be receiving its 12V feed before you press the start button on the computer.

STEP 5 - Press the start button on the computer.  The computer should start normally.

STEP 6 - Take note of the maximum amperage draw displayed on the lab psu at startup (i.e. from the time you press the power button to the time XXHE is loaded), at idle (i.e. when the computer is sitting there with XXHE open, but is not playing music or doing any other tasks), playing music, pressing Alt-X to come out of unattended mode, and shutting down the computer.  This should be done multiple times with both minimised o/s and not minimised o/s

STEP 7 - Post the results in this thread

 


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 09, 2013, 05:24:58 am
#2 of 2 ways to measure the current draw at the P8 CPU Socket on the Mobo

If you DON'T have a lab supply that displays the voltage and current draw, but you do have a multimeter this is still very easy.

STEP 1 - Unplug your XXHE computer from the wall.  Remove the 8 pin plug from the P8 CPU socket on the motherboard.  Plug in the 8 pin EPS extension cable (such as this (http://www.ebay.com.au/itm/male-to-female-8-Pin-ATX-12V-CPU-EPS-P4-Power-Extension-connectors-Cable-TR-/400551972300?pt=AU_CablesConnectors&hash=item5d42c20dcc)) and cut all the POSITIVE wires in half (the yellow ones, not the black ones).  With the yellow wires that are connected to the compute PSU, twist them together and screw them into a terminal strip so that all four wires go into the same socket of the terminal strip.

STEP 2 - On the opposite side of the terminal strip screw in the positive probe of the multimeter.

STEP 3 - Screw the negative probe of the multimeter into a different socket of the terminal strip.

STEP 4 - Twist the remaining four yellow wires (that you cut earlier) into one group and screw them into the terminal strip opposite the negative probe of the multimeter.

STEP 5 - Plug the free end of the extension cable, with the multimeter wired into the middle, into the P8 socket of the motherboard.

STEP 6 - Make sure you don't have any potential shorts anywhere and then plug the computer power supply back into the wall and press the start button.  The computer should start normally.

STEP 7 - Take note of the maximum amperage draw displayed on the multimeter at startup (i.e. from the time you press the power button to the time XXHE is loaded), at idle (i.e. when the computer is sitting there with XXHE open, but is not playing music or doing any other tasks), playing music, pressing Alt-X to come out of unattended mode, and shutting down the computer.  This should be done multiple times with both minimised o/s and not minimised o/s

STEP 8 - Post the results in this thread


Note that in the photos below I have also directed the black wires (ground) through the terminal strip.  This is not necessary, they can be left entire and uncut.



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 09, 2013, 08:38:50 am
Super stuff Anthony !

Btw, when you have all still connected, you might consider Alt-x in Normal OS Mode just the same. Just do not tick all the "shut down" buttons and use Unattended as usual (oh, you can use the "shut down" stuff just the same but I'm not sure which comparison would be the most fair).
And of course, is using Alt-x in Normal OS Mode in the game anyway ? maybe not.

FYI : I can tell (by guarantee) that your measured 1.2A during playback can be pulled down to 0.5A. This is a bit unsafe though, so count 0.72A (this is processor frequency related which can be brought down more). Notice that I talk about super-stable current draw and not about your measurend 0.15A "swing range". For that matter, my 0.5A is related to the upper side of your swing, while my "super stable" setting would use the under side (so, roughly 0.49A now - didn't do the math).
I am not sure whether this can count for booting, although I do know that a certain BIOS setting would let it stick to 1.2A (not my 0.49A !). But this setting is not the best for SQ, so actually we can't use that.

I wonder, can't we make a comparison with the 3930 by means of "deduction" or how to name it ? So, you have some (one only) type of hdd in there for the OS (preferrably a 2.5" because I have that) and now you measure what happens at booting for the total draw (like you did previously actually). I do the same, and it should be higher. The difference should be caused by the CPU, so we know what the 3930 does. Same for the other measurements.
Or would that be too rough ?

Thanks mate,
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 09, 2013, 09:27:45 am
Super stuff Anthony !

I wonder, can't we make a comparison with the 3930 by means of "deduction" or how to name it ? So, you have some (one only) type of hdd in there for the OS (preferrably a 2.5" because I have that) and now you measure what happens at booting for the total draw (like you did previously actually). I do the same, and it should be higher. The difference should be caused by the CPU, so we know what the 3930 does. Same for the other measurements.
Or would that be too rough ?


Peter, I think that it would be best to directly measure the cpu socket with the i7-3930 installed because this is where the cpu draws all of its power (I think all).  You would have some sort of lab psu there...maybe fork out for a 4 pin or 8 pin extension cable or even just buy a 8 pin male plug, some EPS pins and make your own extension cable.  It is a bit fiddly but this is essential information.

FYI : I can tell (by guarantee) that your measured 1.2A during playback can be pulled down to 0.5A. This is a bit unsafe though, so count 0.72A (this is processor frequency related which can be brought down more). Notice that I talk about super-stable current draw and not about your measurend 0.15A "swing range". For that matter, my 0.5A is related to the upper side of your swing, while my "super stable" setting would use the under side (so, roughly 0.49A now - didn't do the math).
I am not sure whether this can count for booting, although I do know that a certain BIOS setting would let it stick to 1.2A (not my 0.49A !). But this setting is not the best for SQ, so actually we can't use that.


Very interesting stuff Peter...looks like there is more to be gained here.  It certainly looks like the size of the 12V rail for the CPU will be determined by the shutdown current draw which is at least 5A on my system and probably more on yours.

Regards,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 09, 2013, 10:13:19 am
Quote
Peter, I think that it would be best to directly measure the cpu socket with the i7-3930 installed

Of course. And you did make this nice layout of it all for a reason obviously. But before I am the one to do it ... we are all quite busy with completely different things, and I don't see this going in between the jobs.

So just the question : Is someone going to do this for us ?

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 09, 2013, 10:23:10 am
P24 ATX Socket Pins Required by Motherboard

This afternoon I played around with the P24 socket which is the main socket on the mobo that carries the current to run the board, fans, USB ports, PCIE ports et cetera.  Because all motherboards seem to be selective in which parts of the ATX specification (http://www.formfactors.org/developer%5Cspecs%5CATX_ATX12V_PS_1_1.pdf) they choose to conform with I decided that I would try to figure out some rough rules for the power rails (+3.3V, +5V, +12V, -12V) and associated ATX pins.  What I did was get a P24 extension lead (like this one (http://www.ebay.com.au/itm/221162438136?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)) and basically push out one pin at a time, startup (or attempt to startup) the XXHE PC and play some music.  The result is summarised in the graphic attached to this post.

Basically, the Asrock X79 Extreme4-M motherboard does not use the -12V rail, the 'Power Good' pin or the +3.3v sense pin.  Each of the +3.3V/+5V/+12V rails are represented by multiple pins in this socket, but the motherboard needs at least one pin (any pin) representing each rail to be powered.  It does not matter which pin this is just so long as at least one pin from each rail is powered.

What does this mean?  It tells me that even though each pin for a specific voltage is represented in this socket a number of times, they all come into one on the motherboard so there is probably little to be gained by even trying to power each pin from a separate rail.  Therefore I propose to measure three separate rails (+3.3V, +5V, +12V) into this socket by joining the wires of each of these rails into one and then running them from my lab psu.  

The '3.3V Sense' pin (#13) is used to allow the power supply to account for excessive cable drops on the +3.3v rail.  I assume that this means voltage loss due to cable resistance and the associated +/- 5% DC voltage regulation for the rail.  If this is the case I think that this can be overcome by making sure we have 3.3v at the P24 ATX socket on the motherboard and not just at the power supply.  Someone please correct me if I am wrong.

I also hope to be able to find an easy way to convince the motherboard to boot by using the +5v Standby pin and the 'Power On' pin.  The +5v Standby pin needs to be active whenever AC power is present and provides a power source for circuits that must remain operational when the computer is turned off (enables the power button on the computer case to work among other things).  The 'Power On' pin could be the tricky one, but I have a few idea on how to get it functional which I will try out when it comes to that.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 09, 2013, 10:40:48 am
Anthony,

I really don't know anything about MoBo layouts (but have a hunch that starts to happen from of now), but those several same Voltage pins possibly allow to spread the current over different traces on the PCB. So, if you'd now use one connection only, something may get hot somewhere ?

What would be allowed though, is using the one single source for the e.g. 3 connections. Of course that one source now must be rated higher (A) then 3 singles sources. And yes, you have one lab PSU only, so for you it is not so obvious maybe. But look at what comes from your PC PSU and how the 3x etc. is organised inside (I am almost sure that at least the 12V is spread over to separate sources - and not just a Y cable split).

Again, I don't know, but take it into consideration please.
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 09, 2013, 10:53:07 am
Hey Anthony,

Be careful not losing a possible new post because I am going to move this topic to a new board somewhere. :)

I will do this 15 minutes from now ...
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 09, 2013, 01:36:56 pm
Anthony,

I really don't know anything about MoBo layouts (but have a hunch that starts to happen from of now), but those several same Voltage pins possibly allow to spread the current over different traces on the PCB. So, if you'd now use one connection only, something may get hot somewhere ?

Yes, that was what I was thinking.  The fact that any pin on a rail is enough to power everything indicates that they have been split for a reason, heat is probably it.


What would be allowed though, is using the one single source for the e.g. 3 connections. Of course that one source now must be rated higher (A) then 3 singles sources. And yes, you have one lab PSU only, so for you it is not so obvious maybe. But look at what comes from your PC PSU and how the 3x etc. is organised inside (I am almost sure that at least the 12V is spread over to separate sources - and not just a Y cable split).


I will look into this.

Thanks,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: Nick on October 09, 2013, 08:06:41 pm
Anthony hi,

Another consideration is the sequencing of the power rails during turning on. There mobo will expect a "power good" signal to be provided after the rails are sequenced on.

I had a look at options for building a linear supply a while ago but did not get further than reading arround what the supply would need to do.

Take a look here the "power good" information is half way down the page.

Cheers Nick.

http://www.tomshardware.com/reviews/power-supply-specifications-atx-reference,3061-2.html


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 10, 2013, 12:26:23 am
Hi Nick,

Yes, the 'Power On' may be a difficulty, but see my next post for what I have measured with this rail.

Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 10, 2013, 01:17:43 am
P24 ATX SOCKET CURRENT DRAW MEASUREMENTS

So last night I got out my trusty multimeter and hacked into the P24 Extension cable that goes between the motherboard and the P24 plug of the BeQuiet SMPS.  My aim was to figure out the current draw of the various rails and ancillary pins.


12V Rail

There are two 12V pins on the P24 socket each of which will successfully power up the mobo without the other being connected.  I cut both wires, twisted the mobo end of the cut together, removed one supply wire from the supply side so that only one 12V wire was coming from the SMPS and made the measurements below...

o/s StateStartup      Music      Shut-Down     
Maximised (no cpu fan)0.83A0.48A0.56A
Maximised (cpu fan plugged in)      0.93A0.59A0.85A
Minimised (no cpu fan)0.81A0.57A0.81A
Minimised (cpu fan plugged in)0.92A0.57A0.81A

The 12V rail powers the cpu fan in the XXHE PC so I though it prudent to measure with the fan connected as well as disconnected.  The amperage varied when I pressed a key or moved the mouse, so perhaps the PS2 ports are run from this rail also.  As you can see the fan does not make much of a difference to the power draw on this rail, neither does minimising the o/s.



5V Rail

There are 5 5V pins on the P24 socket and each pin alone will power up the mobo if all the other 5V pins are not powered.  I cut all the 5v wires, twisted the mobo end of the cuts together into one joint, remove all but one cut 5V wire from the SMPS side of the cuts and made the measurements below...

o/s StateStartup      Idle      Music      Shutdown     
Maximised      4.0A2.2A2.2A to start, 2.0A stable      2.3A
Minimised4.1A2.2Astart 2.2A, stable 2.0A2.2A

Like the 12V rail, the 5V rail does not seem to be impacted by the sate of the o/s.  I am not confident that 4.0A peak during startup has been recorded accurately because it is displayed on the multimeter as a rapidly changing amperage which may mean that the peak has been missed.



3.3V Rail

There are three 3V pins in the P24 socket each of which will successfully run the mobo in the absence of power to all of the remaining pins.  I cut the 3.3v wires, twisted the mobo side of the cuts wires together into a single joint, removed  all but one of the cut wires from the SMPS and made the measurements below...

o/s StateStartup      Idle       Music      Shutdown     
Maximised      1.43A1.42Astart 1.43A, stable 1.35A1.42A
Minimised1.43A1.38Astart 1.4A, stable 1.34A      1.4A

Like the 12V and 5V rails, the 3.3V rail does not seem to be impacted by the state of the operating system.



Power On Pin

I was unable to measure the voltage variations of this pin.  It seems as though the act of measuring this voltage with either of my multimeters is enough to drop the voltage out of spec and the mobo will not power on.  I could, however, measure the amperage draw which was a consistent 150uV which must be present whenever the computer is turned on.  If the pin was pulled when the computer was powered on it instantly performed an ungraceful shutdown.  When the computer is turned off, this pin does not draw any current.  The literature indicates that this pin must be supplied +5V whenever the computer is on.



+5V Standby Pin

This pin will supply power to the motherboard even when AC is connected and the computer is turned off.  Measurements were as follows...

o/s StateComputer Off, AC On      Startup      Idle      Music      Shutdown     
Maximised      0.353A1.0A0.9A0.9A1.0A
Minimised0.353A1.0A0.9A0.9A1.0A

Draw from this pin was identical regardless of o/s state.  The ATX Standard specifies 1A minimum for this pin, with a recommendation for 2A to be provided to meet future requirements.



Summary
At this stage, a maximum of 5 separate rails could be run into the P24 socket alone: +12V 2A min.; +5V 5A min.; +3.3V 3A min.; +5V 0.5A min. (power on); +5V 2A (Standby).  Likewise, a minimum of 3 separate rails may suffice if all the +5V rail were combined.  The real question is whether the extra two rails would be worth the extra expense.

The next step is to have a look at some ATX psu's to see whether all the pins for each voltage are generated from the same rail, or whether the load is split according to pin.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 10, 2013, 03:48:03 am
Just looked at the specs for the BeQuiet L7-530 SMPS that Peter recommends (and I use) in the XXHE PC.  There are two +12V rails: one for P24 ATX socket and PCIe ports; the second for P8 cpu socket, molex and sata peripherals (video cards, HDD, SSD, USB cards et cetera).  As far as I can tell the +3.3V and +5V rails are shared between the motherboard and peripherals.

I wonder how much there is to be gained by separating power supply to these components to minimise interplay?

Another interesting thing is the ripple rating of the BeQuiet.  Both +12V rails have a ripple/noise (max.) of 120mV while the +5V/+5V Standby/+3.3V rails are rated at 50mV maximum.  Compare this to the supposed specs. of my lab linear psu of 1mV rms, so I should be able to hear a difference if the ripple is an issue.

It's time to organise an oscilloscope.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 10, 2013, 08:50:10 am
You are really into this eh ? Well, I wonder when (!) this is going to bring us other things ...

12V Rail

There are two 12V pins on the P24 socket each of which will successfully power up the mobo without the other being connected.  I cut both wires, twisted the mobo end of the cut together, removed one supply wire from the supply side so that only one 12V wire was coming from the SMPS and made the measurements below...

o/s StateStartup      Music      Shut-Down     
Maximised (no cpu fan)0.93A0.59A0.85A
Maximised (cpu fan plugged in)      0.83A0.48A0.56A
Minimised (no cpu fan)0.81A0.57A0.81A
Minimised (cpu fan plugged in)0.92A0.57A0.81A

The 12V rail powers the cpu fan in the XXHE PC so I though it prudent to measure with the fan connected as well as disconnected.  The amperage varied when I pressed a key or moved the mouse, so perhaps the PS2 ports are run from this rail also.  As you can see the fan does not make much of a difference to the power draw on this rail, neither does minimising the o/s.

First the notice that those first two measurements may have their results twisted ? If not, something (cpu) heats up causing more current.

Then, in order to test that "PS2 movement draw", go into Minimised, start playback and on that black screen move the mouse. It now totally depends on what you see for a difference with your earlier tests regarding this;
I think it can be so - at least partly - that the mouse movement shows less draw now. If that indeed is so, that "over" part you measured earlier is just CPU usage. Notice the importance of the mouse needing to be over a black screen. BUT :
Writing this, I now realize that this won't be a valid test for W8 because that black screen is a "form" as such. The test would only be valid in W7 or when you'd be able to have "nothing" there.

Ok, sorry, never mind this. I don't think knowing the result of this is much useful anyway. But what I was actually heading for is the more precise knowing what does what for possibly noise creation. So as you know I advise PS2 connections. But what when USB is used after all ?
This is more complex because in the end this also heads for shutting down USB2 completely, which in your situation can't be done unless you have such a separate PCI USB3 card (then you can shut down USB2 while your NOS1 keeps on working on the card).

And on the other hand ... I am changing the subjects as it seems ...
But no necessity to give you pointers to this regard, because I see you are "rolling" into such subjects (of noise) anyway automatically. And FYI (because I never told you), this is how the 0.5mV/Div scope comes handy later; you just might be able to measure noise differences anywhere outside of the PC (or at "outputs" like USB) because of changes. "Just" because 500uV is actually very much but with that per division (of 1cm of height) there's a bit more to see than that of course.

Hey, it seems you like this much eh ? Well, I hope you can still play some music once in a while ? :wacko:

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 10, 2013, 09:20:15 am
Nice pickup on the 12V rail Peter.  I have checked my notes and edited that post so that it is now correct.


Ok, sorry, never mind this. I don't think knowing the result of this is much useful anyway. But what I was actually heading for is the more precise knowing what does what for possibly noise creation. So as you know I advise PS2 connections. But what when USB is used after all ?
This is more complex because in the end this also heads for shutting down USB2 completely, which in your situation can't be done unless you have such a separate PCI USB3 card (then you can shut down USB2 while your NOS1 keeps on working on the card).


I have shut down all my USB2 and USB3 ports because I use the PCIe USB3 card from PPAstudio.

But no necessity to give you pointers to this regard, because I see you are "rolling" into such subjects (of noise) anyway automatically. And FYI (because I never told you), this is how the 0.5mV/Div scope comes handy later; you just might be able to measure noise differences anywhere outside of the PC (or at "outputs" like USB) because of changes. "Just" because 500uV is actually very much but with that per division (of 1cm of height) there's a bit more to see than that of course.

Hey, it seems you like this much eh ? Well, I hope you can still play some music once in a while ? :wacko:

Peter

Oscilloscope's!!  When you want to buy a cheap one they are all too expensive and even then they may generate too much noise to be entirely useful.  :grin:

I am enjoying tinkering with this stuff and this is a subject that I have been considering for a while now.  Don't worry though, I am listening to plenty of music.

Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: pedal on October 10, 2013, 09:43:16 am
Anthony,

As a layman I consider these measurements to be of significant value, because they *prove* (partly) why different PCs sounds different.

Different motherboard, soundcard, OS, etc, taxes the power supply completely in different patterns.  Knowing that the PSU is a weak link in common PCs, it is clear that this behaviours influences noise and sound quality.
-PSU being the heart of all electrical Hi-Fi equipment.

As Peter points out, all your measurements are perhaps not perfectly carried out yet, there are still areas to improve/discover. However the basic conclusion is clear.

These kind of measurements also "proves" why (partly) XX highend performs better than other music player software, because functions as "minimize OS, etc" allows a more even and lesser taxing of the PSU.

(This should be a wake up call for ignorants who believes that anything beyond "Foobar on an ordinary PC" is a waste of money).

Keep up the good work!  :clapping:


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 11, 2013, 09:31:58 am
Thanks for the kind words Pedal.  I am not yet convinced that better power in the XXHE pc will directly improve anything, but I think that the computers power supply may impact other components via the AC lines.  We will see!

Tomorrow I am auditioning my nos1 in a high end system and if I find some time I will pull out my lab LPS and see if a few of us hear a difference.  I will power the P8 cpu socket, my PPAstudio usb card and the ssd.

Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: pedal on October 11, 2013, 01:41:29 pm
Reducing RF from a noisy component: One trick is to take a regular kind of Schaffner filter and REVERSE the direction of the plugs. Then it will filter whatever your PC leaks back to the AC connection.

This trick can be done even on noisy refrigerators etc . But don't tell anybody you have a net filter on your refrigerator, they think you are crazy!


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 24, 2013, 10:55:32 am
How to Boot the Asrock X79 Extreme4-M motherboard without an ATX Power Supply

Yep...got it figured out...I can start the Asrock mobo using a three rail linear supply with ZERO help from an ATX supply.

This afternoons efforts have been focused on getting the mobo to boot reliably.  Based on the previous measurements, my 3 rail lab linear supply is not able to provide enough current (from the fixed 5v 3A rail) for the 5v rail of the P24 ATX socket, so I did a little trick to make the BeQuiet SMPS turn on when disconnected from the motherboard thus bypassing its ATX functions.  The BeQuiet SMPS was used to provide power to the P8 CPU socket and the 5v rail for the P24 ATX socket.  The 3 rail linear PSU was used to provide 12v and 3.3v to the P24 ATX socket and 5v to the PPAstudio usb card.

I improvised a wiring loom for the P24 ATX socket that had the three rails (from two power supplies) and grounds distributed as shown in the attached image.  Note that at this stage the grounds don't seem to be too important because everything has worked with my first semi random attempt at spreading the grounds between the three rails.

To get the computer to boot I had to first start the BeQuiet SMPS (12v in P8 cpu, 5v into P24 ATX) and then start the lab linear supply (12v and 3.3v into the P24 ATX socket).  It does not matter how long I wait to turn on the second psu, (I tried from 0.5s to 30s), because the computer fires up every time when I press the power button on the front of the case.  The computer will NOT boot when the BeQuiet SMPS (5v P24 ATX and 12v P8 cpu sockets) is turned on AFTER the 12v and 3.3v rails into the P24 ATX socket.  I am not sure whether it is the 5v rail or the P8 CPU rail or both that must be turned on before the remaining rails into the P24 ATX socket, but that can be determined at a later date.  The important thing is that I can reliably turn the computer on and off with a rudimentary ATX sequencing.

There is one caveat at this stage...for those familiar with the operation of the light on the front power button on the  Silverstone GD06B case...well at this stage I have not spent the time to get that working properly.  It comes on as soon as the 5v rail into the P24 socket is powered regardless of whether the computer is on or not.  The remedy may be as simple as doing something different with the 5v 'Power On' wire into the P24 ATX socket, but I have not spent the time to figure it out as yet.  At this stage the 5v 'Power On' wire is grouped with all the other 5v wires on the 5v rail.

The sequence of events to get the Asrock X79 Extreme4-M motherboard to boot from a non-ATX power supply is as follows:

  • Power on the 5v rail into the P24 Socket and the 12v rail into the P8 CPU socket (not sure if both are required to be started first at this stage)
  • Following a small delay, power on the 3.3v and 12v rails into the P24 CPU socket as well as other rails to SSD's and USB cards et cetera
  • Press the start button on the front of the computer case


Once the computer is successfully shutdown (either by Windows or the power button on the computer case), the order that the rails are turned off does not seem to matter at all for the next boot.  There will be some issue making sure that the computer is fully shutdown before cutting power, so at this stage I think that it will have to be a manual procedure i.e. when windows goes blank after shutdown then turn off the power supply.

Anyway, this took me about 3 hours this afternoon to figure this all out and I am feeling a tad 'special' because I thought it may have taken several weeks on and off, but now we have a way forward for a bespoke FULL linear power supply for the XXHE pc.

Cheers,

Anthony
 


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 24, 2013, 11:15:28 am
Wow again Anthony !

One remark :
At least with Windows 8 (7 I don't know) it has occurred to me that the system can remain active for a second or 10 after all other tells you Windows has shut down (monitor was shut off by the system as well).
Of course this is easy to see by watching the leds inside (but led at the power button shows it just the same). And I must add that I am not so sure I saw this always (read : maybe BIOS/XXHE settings can imply this).

Of course I can't tell what is happening during that stage (because Windows "tells" all has been shut down anyway) but in your (due) case it could be difficult to see when the power really can be cut. I mean, if Windows has not shut down at all really, you will be cutting whatever last process.

The least I theoretically could do for you is watch the disk light suring that last stage, but I am reluctant to do so reliably because as you will know this is not easy to see through the same space and same led color of the power button. So, I already dropped my ever and always looking at the disk activity for this PC (which I always regard the most important) because it can't be seen anywhere when flashes are very short.

Hope this helps ...
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 25, 2013, 12:06:51 am
Thanks Peter,

The power down thing may be a more difficult issue than the power on difficulties.  To do it right some transistor logic will be required using the signal from the motherboard that is transmitted to the power supply via the 'Power On' wire in the P24 ATX socket.  Providing this logic is far beyond my current knowledge so I would have to defer that to others.

A simpler way may be to wait ten seconds or more before turning off the linear power supply or even using a short piece of optic cable to show the status of the mobo lights on the outside of the case so that we can be certain that the mobo has powered down before we cut power to the power supply.

Anyway, I think this is a hurdle for later on down the road.  First we have to figure if the LPSU into the XXHE will make a sonic difference.

Peter, have you got any ideas about good linear regulators to use when building a power supply?  The obvious ones to me are the Paul Hynes regs but they are very expensive and a very long wait time.

Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 25, 2013, 03:02:50 am
In the sharing spirit, with Paul (Scroobius) having just purchased a PPAstdio USB3 card like mine, I decided to try the lab linear psu feeding said card to see if it makes a difference.

Well it does make a nice difference.  The NOS1 has already outperformed some really good dacs here at home, but it is even better with the PPAstudio card and even a cheapo lab linear psu.  Blacker backgrounds, better 3D imaging, I can hear more of the room in acoustic recordings, or the 'ambience' as Peter likes to put it...the reverb, the echo et cetera.

So mark that up as one rail that is essential to be powered by the linear psu.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 25, 2013, 09:25:45 am
Quote
Peter, have you got any ideas about good linear regulators to use when building a power supply?  The obvious ones to me are the Paul Hynes regs but they are very expensive and a very long wait time.

Anthony,

No, not really (at all). But this is merely because I never looked into ready products. Okay, not true : http://www.tentlabs.com/Components/Shuntcomp/index.html
I have some 300 of these around which is for a reason. :swoon:
Just doesn't work. Well, not through my eyes.

Coincidentally I very recently designed such a thing in module form and the PCBs for it should have arrived this week but nothing yet (stolen in China ;)). This should show noise in the nV range and it should be able to replace the input caps on the NOS1 boards (+/- 4.9V). But this is very low current (say 300mA max) and I don't think it can be useful for in the PC anywhere.
To make something general is not easy because it depends on the environment and the knowledge of that. So for example, when it is to take 3A then the configuration (of chips used) is different and e.g. 1mV of noise comes from it (just making up some number). However, while this 3A regulator might be applicable throughout (assuming 3A is max anywhere), it is oversized and also "over-noised" for the situation that only 300mA is needed which could show that nV range of noise.

The funny thing is that when you approach it from this angle of "better regulators" you find yourself the PSU to be not important anymore, as long as the power supply rejection (PSRR) of the regulator is very ok. So all is one big mixed bag of design issues (or challenges) and when you'd believe in this approach you can even think of one 12V out of which all 12, 5, 3.3 and beyond voltages are created. Now that one 12V needs to carry all the Amperes together so probably it will be a no-go for that reason (and additional noise), but the whole point is that you only know for real when you sit down for a week at finding chips to do the work needed and with the notice that only after this "research" you will have a consistent design that may show it failed (against the other theoretical solution, also to work out).
May take weeks or months to do it well.

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 25, 2013, 11:19:36 am
Thanks Peter,

Quote
Now that one 12V needs to carry all the Amperes together so probably it will be a no-go for that reason (and additional noise), but the whole point is that you only know for real when you sit down for a week at finding chips to do the work needed and with the notice that only after this "research" you will have a consistent design that may show it failed (against the other theoretical solution, also to work out).
May take weeks or months to do it well.

Wow...righto...I am quite sure that I am not up to the task of designing a linear regulator, I had just assumed that I would be using an existing design and assembling them (at worst) or using an off-the-shelf linear regulator (at best).

For instance, this reg (http://sjostromaudio.com/pages/index.php/hifi-projects/176-ssr03-sjoestroem-super-regulator-power-supply?showall=&start=7) from your part of the world that I could pull out a soldering iron and follow a relatively simple build.  Noise seems fine but the current limit is 1A, so it could only be used to power a USB card or SSD.  I reckon I could build these for about AU$75/50euro each.

5A and 2A loads are going to be much more difficult.

Thanks,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 26, 2013, 01:55:01 am

No, not really (at all). But this is merely because I never looked into ready products. Okay, not true : http://www.tentlabs.com/Components/Shuntcomp/index.html
I have some 300 of these around which is for a reason. :swoon:
Just doesn't work. Well, not through my eyes.


I have had  look at the tentlabs shunts that you linked.  Why do you think this regulator has not worked for your situation?  Noise and output impedance both seem low.  Perhaps the not-published PSSR and transient response figures were too far out of spec.?  I'm just guessing here, trying to figure out what I should be looking for in a voltage regulator.



Coincidentally I very recently designed such a thing in module form and the PCBs for it should have arrived this week but nothing yet (stolen in China ;)). This should show noise in the nV range and it should be able to replace the input caps on the NOS1 boards (+/- 4.9V). But this is very low current (say 300mA max) and I don't think it can be useful for in the PC anywhere.


Actually, the builder of the PPAstudio USB card recommends a 5V 1A power supply but I can't get my card to draw more than 0.02A into the NOS1, which is 20mA, and is well within 300mA range of the regulator you mentioned above.

I have found an article from Linear Audio Magazine that first measures 15 commercial and diy linear regulators and then does blind listening tests when using them to power a line amplifier.  Although the listening tests are relatively meaningless in the context of the XXHE PC project, the measurements of these regulators could be of some use.  The article itself is not free but the graphs are readily available on their website, so I will reproduce some of them below.  Note the Sjostrom measures well in all three graphs below.  It is interesting to note that one of the 'surprisingly good' regs in the listening tests were the Linear Tech devices which the author of the paper attributed to 'fast transient response'.

Anthony




Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 26, 2013, 03:47:01 am
TOTAL DRAW OF XXHE PC

I just realised that I had not published the complete draw of my XXHE PC in this thread.  To do this I plugged my pc into the UPS and let the UPS tell me the draw as the pc performed various tasks.

Whole XXHE PC      Minimised o/sMaximised o/s
Startup98w98w
System Idle58w68w
Playing Music68w at start 58w stable      88w at start 58w-78w in a cycle     
Shutdown78w107w


This information is useful if I end up going a different route with the linear power supply and using a wide range pico psu (eg. 12v - 24v 160w) fed by a single high powered linear power supply.  The pico psu is a tiny dc-dc converter that manages the atx power functions including derivation of the various rails for the P24, P8 and peripherals.  A single 20V 8A supply would be sufficient to run the 160w wide input pico psu.

As you can see from the table above, a 160w wide input pico psu MAY have enough juice to run my XXHE PC, but does it have enough juice to run yours?  This is especially relevant if you run more HDD's or SSD's than me, and use the higher power i7 cpu that is recommended for the XXHE PC.

Anyone care to measure the total draw of their XXHE PC?  I may be able to rule out the pico psu angle if your computers draw much more juice than mine.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 26, 2013, 04:03:53 am
PERIPHERAL DRAW

I thought that I would also share the draw of the two peripherals inside my XXHE PC: a single Samsung 840 EVO 750GB SSD; a PPAstudio V1 USB3 card.

Computer State      SSDPPAstudio V1 USB Card
Computer Off0.25A0.02A
Startup0.44A0.02A
Playing Music0.40A to start 0.05A stable      0.01A
Shutdown0.5A0.01A

The results were identical when the o/s was minimised and maximised.

The SSD is spec'd at 5V 1.4A (written on drive itself) but I never saw more than 0.5A draw at any stage, although it would almost certainly be prudent to be able to supply the recommended 1.4A to the SSD just in case...we would not want it to lose information if it could not find enough juice.

The builder of the PPAstudio USB card recommends 5V 1A.  The NOS1 does not seem to take usb power at any stage, so perhaps we can get away with powering the PPSstudio card with a higher quality and lower current 5V linear supply.  The USB3 standard gives a maximum load of 0.9mA, and considering that I have been able to measure not more than 20mA draw, perhaps a linear power supply around that 100mA (0.1A) will be perfectly suited if only the NOS1 is connected to the card.

Anthony



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: AlainGr on October 26, 2013, 04:14:48 am
The PPA would be a good candidate for the iFi iUSB I suppose. I intend to have a cable made with a USB male A at one end and a molex at the other end with the required 5V...

Alain


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 26, 2013, 12:55:23 pm
Ok, I hooked up a usage meter. I will try my best to make it interpretable but we will soon see that this is a though job.

I used Minimized OS only (at least for now).

Whole XXHE PC      Minimised OS Anthony        Minimised OS PeterSt     
Startup98W92W
System Idle58W52.5W
Playing Music68w at start 58w stable54.5W - 57W

Notice that it is crucial to compare the XTweaks settings; mine you see below. Even more crucial is that by this means I finally found that the Cool when Idle setting makes all the difference in the world. Look here : Re: XTweaks : Cool when Idle and Windows 8 (http://www.phasure.com/index.php?topic=2442.msg28680#msg28680).

General remarks :

Mains is ~222V today.

Looking at thee table above, my figures show consistently lower (all sort of the same percentage lower). My conclusion from that is that Anthony can have his processor frequency at 1200MHz while mine runs at 720MHz. And yes, since this board his here anywhere I will create a topic about how to do that.

The 2648L Xeon processor Anthony uses consumes (well, dissipates) 70W max. My 3930 is rated at 135W. Now careful :
Assumed the both processor types (completely different by themselves) use the same "die" technology, all what happens (or may happen to my expectation) is that the max usage occurs at the max demand. Here is already a difference to notice because the 3930 is 3.8GHz in turbo mode while the 2648L is 2.2GHz in that mode. The 3930 is 6 core while the 2648L is 9 core, but turbo mode happens in one core only. Otherwise the 3930 is 3.2GHz and the 2648L is 1.8GHz.

Still there ?
Nothing compares, also knowing that turbo mode won't be used at my XTweaks settings, plus my 3930 won't exceed the 720Mhz by a singly cycle ever. So ...

What I try to say is that probably there is no difference as long as the both processors use the same frequency *and* would have the same number of cores - which they have not. :swoon:

Music Playback

If it were for me, this never can be stable and which is also what I see happening. To see this well the SFS must be somewhat higher (I set mine to 120 for this) pluf of course the meter must respond fast enough. Anyway, what I see is that loading a trackpart consumes 2.5W.
I tried to see a difference between loading from RAMDisk and loading from the spinning disk, but there is none that I can see.
I also tried vary the Clock Resolution and Q1, but no difference to be seen.

Peripherals

My test was with one 2.5" spinning disk in there (in the removable bay). So given figures are for that. Otherwise the only device connected was the NOS1. So, 52.5W idle.

Connecting a USB3 disk (self powered !) implied an additional usage of 1W (when settled). Otherwise maybe 0.5-1W more (right after plugging it in).

Inserting a 3.5" spinning disk implied a steady 6.5W more, which is quite a lot compared to the 52.5W without it.

Sadly I could not test a 2.5" disk or SSD because the bay for it was occupied by the OS disk. But assumed the usage of that is similar then without disks something like 46.5W would be the result for the whole PC.

Might it be of importance : Idle figures are with LAN running, while Playback figures are with LAN shut off. It is a bit cumbersome to test this better, however, pulling the LAN cable makes a difference of between 0.5-1W.

Inserting a random USB2 stick in the USB2 port (after settling) doesn't seem to make a difference and otherwise it is under 0.5W (my meter has no better resolution than 0.5W). Inserting that in an USB3 port (all front side) I see 0.5-1W.
A USB3 stick same story.

Boot

Thinking this is all about what a LPSU should be able to cope with, I think this is crucial data :

Once the frequency ratio is taken out of the default in the BIOS, in "BIOS stage" (which is the same as during booting) no turbo frequency will occur, while otherwise I'm fairly sure it does. I did not test this thoroughly (I mean, ever back), but we know that when we set up the PC for the first time all the fans should run at max, until we changed that ratio (to any value, also higher than 3.8 ) and when then a reboot is applied all is safe to look at the BIOS for a longer time.
Of course such behaviour should be visible with the usage meter just the same.

I think it will be so that when for example the ratio is set to 1.2 (less is not possible) the usage will be relative to that when in BIOS mode hence when the PC boots. In my situation (see table) this implies 92W max, but which 92W did not really occur during "POST" but much later.

Vague will be that while this 92W occurs later and will not come from "raw" motherboard behaviour, it will come from the more heavy OS activities BUT which in my case are already done under the 720MHz frequency. Now, to me it seems not important how much the raw usage is during "POST" because this OS usage is just the max occurring. In that situation all cpu cores will be active and thus the most draw is implied at that stage. I just started a FLAC album which also uses all cores (hyperthreaded) and during a short stage the usage is 68W. Notice though that this is I/O intensive and no way a core will be at 100% because of this. This story is more complicated because of (cache) memory to RAMDisk operations here, but the key point is that this 68W never exceeds the 92W during booting.

It seems that 92W is the maximum usage and this is only during a short while (but never mind the short while because nothing should be dangerous.

Current draw

Just because the question may be asked :
I am not sure what I see is reliable; it is so much lower than what Anthony's tables show that I must think about it. Notice it is measured through the same meter. Still what I see is consistent with the Watts used. But for example : 0.265 - 0.280A during Playback which nicely relates to the 52.5-57W I see. The 92W max used compares to 0.44A max used (boot).
So, it may be consistent, but I don't think this can be correct.

Peter


Title: MoBo shutdown time
Post by: PeterSt on October 26, 2013, 01:20:57 pm
Since I had to reboot anyway I watched the time before the power led went off after the monitor went blank and powered down :

A sheer 22 seconds.

:scratching:


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 26, 2013, 01:26:37 pm
Yea, I see now where I didn't understand my amperage draw;

I was so smart to mention my mains voltage because this is related when we need the amperage, but ... :fool: that is of course not the draw from 12V etc. internally ...

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 26, 2013, 10:49:28 pm
Nothing compares, also knowing that turbo mode won't be used at my XTweaks settings, plus my 3930 won't exceed the 720Mhz by a singly cycle ever. So ...

What I try to say is that probably there is no difference as long as the both processors use the same frequency *and* would have the same number of cores - which they have not. :swoon:

My Xtweaks are almost identical to yours Peter (my Balanced Load is 45), and my cpu was set to 'Auto' which means it overclocks at will, which it does, so it goes up to about 2.2GHz and was dropping as low as 1.6GHz.  This was the default setting in the BIOS, so that was were the measurements were made.  I have performed no BIOS tweaks in relation to the RAM or CPU.


Current draw

Just because the question may be asked :
I am not sure what I see is reliable; it is so much lower than what Anthony's tables show that I must think about it. Notice it is measured through the same meter. Still what I see is consistent with the Watts used. But for example : 0.265 - 0.280A during Playback which nicely relates to the 52.5-57W I see. The 92W max used compares to 0.44A max used (boot).
So, it may be consistent, but I don't think this can be correct.


I think our amperages are different during playback for a number of reasons, the most important of which is that the amperages that I have measured to date have been inside the computer at DC, while yours is 222V AC before the computer.  Your AC wattages will be much more accurate than mine because I have plugged into a UPS that updates the screen at about 1Hz and seems to have a resolution of about 10 watts (i.e. I see 58w or 68w but nothing in between).  Also, as mentioned earlier, although my Xtweaks are almost the same as yours Peter, until now my CPU ratio in the BIOS has been set to 'auto' which means that it under and overclocks at its own discretion, so my clock frequency varies with load.  Of course I will change this at a later date.  Another thing to contemplate are RAM timings...have you changed yours Peter?

Thanks so much for doing this Peter, it certainly does look like we can go down the pico psu + single linear supply route for the mobo if we need to.

Anthony


Title: Re: MoBo shutdown time
Post by: acg on October 26, 2013, 10:53:57 pm
Since I had to reboot anyway I watched the time before the power led went off after the monitor went blank and powered down :

A sheer 22 seconds.

:scratching:

I also had an unusually long shutdown last night...a solid 20-30 seconds after the light went off.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 28, 2013, 03:32:06 am
PC POWER SUPPLY SUPERVISION

After several worthless google searches I have come up with the following information for a way to make a linear ATX supply that will start ANY atx power compliant pc...

Google search "PC Power Supply Supervisor" and you will come up with a plethora of chips that do the ATX power stuff for us...for example (http://www.hardwaresecrets.com/datasheets/SG_SG6516.pdf).

A good result...with a little effort we should now be able to make a linear ATX supply that will start and stop any pc.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 28, 2013, 11:09:42 pm
Hi all,

I thought I would post a couple of pictures of different design approaches for the ATX psu.

The first photo below shows a three rail linear psu that puts 7A into the three rails of the P24 ATX plug and contains the appropriate chip for handling the ATX power sequencing in conjunction with the motherboard.  Nice...I think that something along these lines would be an excellent final product and very achieveable.

The other end result is something like this Teradak photo.  Note that the first picture will also require passive cooling (the heatsinks) and multiple transformers.

Which layout would you would prefer, the circuit board or the box of wires?  I think we may be able to get a circuit board of this type into the XXHE PC (to keep the wire very short from the regulators to the motherboard and peripherals) and have an external box containing the transformers.

Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: CoenP on October 29, 2013, 12:03:08 am
I think the linear psu will run quite hot especially when challenged, not an ideal match with a hot running processor in one casing. Regulators have to drop voltage to operate so amperes=heat. You will need an awfull lot of cooling surface to keep within thermal operating range of the regulators. To get the necessary thermal resistance with a small cooling surface you may have to resort to active cooling.

Furthermore the 7+ amps let the voltage droop and increase the ripple on the input of the regulator. To fight that you need a lot of smoothing capacitance or a higher input voltage (which means even more heat). This may not be at the important music playing moment, but you really have to overspecify the transformers and capacitance nog to run into out of spec voltages on start/shutdown transients.
(To get the idea: in the priomordial phase all computers used to have -large- linear supplies. You can still find the very large capacitance, low voltage "computergrade" capacitors that were specified in surplus stores)

I think the teradac option and build looks sound to me: plenty real estate, sufficient capacitance, necessary ss for regulation, big recitifiers and a large cooling surface.
I ve been thinking of a setup that provides additional stabilised voltages to the pc wherefrom the voltages of the sata drives/PCIe card will be stabilized in the pc or any "low power" powerline.

I thought of this as a too big a project to pull off in my spare time. I also wondered and still do if a linear supply in combination with multi picopsus is the way to go. As i stated before, it may just be the switching input with PFC on the AC alone that is the culprit of the "lesser" sound of switching psus. You may reap 80% or more of the sonic benefits when changing that input to a linear one providing ie 24 or more Volts and have the wide range picos do the supply duty to the pc components. The 24v+ is just to minimise the current for a given power requirement (with only 4A you allmost have 100Watts available...) and ease the design of the linear part of the supply. Remember that there is allways some serious switching action on the motherboard to provide the cpu with 50-100Amps@1.5V from a 12 V powerline...

Regards, coen


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 29, 2013, 01:04:11 am
Thanks for the reply Coen.  Sometimes I think I am talking to myself in this thread!

I think the linear psu will run quite hot especially when challenged, not an ideal match with a hot running processor in one casing. Regulators have to drop voltage to operate so amperes=heat. You will need an awfull lot of cooling surface to keep within thermal operating range of the regulators. To get the necessary thermal resistance with a small cooling surface you may have to resort to active cooling.

I don't think we will get anywhere near 7A on any rail of a linear psu for the XXHE psu.  Two 5A rails, two 2A rails, two 1A rails and a 0.1A rail are all that could possibly be used (not all will necessarily be worthwhile, but that is the most that could be jammed in there).  On top of this the XXHE PC in its standard case has three case fans (plus at least one extra fan slot possible I think) and two cpu fans, so the active cooling is already in place.  Pull out the SMPS and the expansion drive bays and there is 30cm x 12cm x 12cm to fit in some regulators inside the Silverstone GD06B case so there is some scope at least.  Transformers could go outside.

Furthermore the 7+ amps let the voltage droop and increase the ripple on the input of the regulator. To fight that you need a lot of smoothing capacitance or a higher input voltage (which means even more heat). This may not be at the important music playing moment, but you really have to overspecify the transformers and capacitance nog to run into out of spec voltages on start/shutdown transients.
(To get the idea: in the priomordial phase all computers used to have -large- linear supplies. You can still find the very large capacitance, low voltage "computergrade" capacitors that were specified in surplus stores)

I understand your capacitance/voltage/transient points from  a 'sounds good in theory but have never done it for myself' perspective.  The aim of the project is to have a reasonably priced supply that optimises playback quality with the XXHE PC and NOS1...so while, as you say, it is all well and good to have a computer that works as well as it can whilst playing music, it still does need to be able to startup and shutdown properly.  We now know how much current is needed to achieve these things...the challenge now is to 'right size' everything and minimise the noise in the XXHE PC...which is where I need help. 

I think the teradac option and build looks sound to me: plenty real estate, sufficient capacitance, necessary ss for regulation, big recitifiers and a large cooling surface.
I ve been thinking of a setup that provides additional stabilised voltages to the pc wherefrom the voltages of the sata drives/PCIe card will be stabilized in the pc or any "low power" powerline.


I reckon it looks good to me too, but I have a good idea of how much that case costs and it is substantial - probably more than half the total cost of the supply.  This is another reason that I think it may be worthwhile investigating making use of the active cooling already in the XXHE PC.

I thought of this as a too big a project to pull off in my spare time. I also wondered and still do if a linear supply in combination with multi picopsus is the way to go. As i stated before, it may just be the switching input with PFC on the AC alone that is the culprit of the "lesser" sound of switching psus. You may reap 80% or more of the sonic benefits when changing that input to a linear one providing ie 24 or more Volts and have the wide range picos do the supply duty to the pc components. The 24v+ is just to minimise the current for a given power requirement (with only 4A you allmost have 100Watts available...) and ease the design of the linear part of the supply. Remember that there is allways some serious switching action on the motherboard to provide the cpu with 50-100Amps@1.5V from a 12 V powerline...


I think that you could well be right that a picoPSU fed a single linear rail may provide a solid benefit Coen, but as of yesterday I think I can make my own fully functioning picoPSU (minus the switching regulators), and may be able to provide three high quality rails into it for around the cost of a picoPSU plus a good high wattage off-the-shelf linear psu.  That has got to be worth a shot.

If I believed everything that I read online I would tell you that in order of sonic gain the best things to provide linear power to are:  USB card; o/s drive and P8 cpu socket. The great majority of people give up with the P24 socket and simply provide linear power to a picoPSU, but the few that have bothered to do this well report a sonic gain.  The problem with the picoPSU is that it is unlikely to power up the XXHE PC in its standard un-optimised form.

And yes, there are plenty of switching supplies on the motherboard but there is nothing I can do about that.  I have read about providing linear power directly to RAM and also of changing the motherboard oscillators with higher quality units, but they are thoughts for another day.


So where I am at right now, is that I know how much power to poke into various parts of the XXHE PC, and I am pretty sure I can knock up a little circuit board to manage both the linear power supply and the motherboard, but I don't know how to design and construct high performance voltage regulators, so I am looking for help.

Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: pedal on October 29, 2013, 07:34:22 am
Thanks for the reply Coen.  Sometimes I think I am talking to myself in this thread!

Anthony, I do read it carefully but I don't have much to add about the tech talk which is above my capability.
I do, however, intend to purchase both the XXPC and your PSU when it becomes available.

Keep up the spirit and many thanks for the research you provide here!

:-)


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 29, 2013, 08:27:28 am
Thanks for the support Pedal.  I will plug away at this but I am now at the limits of my recollection of high school electrical theory (it was 25 years ago!! - how did that happen??).  I really need help with a lot of the stuff from here on and I can see myself wasting a LOT of time if I am allowed to trudge off down the wrong paths.

Saying that, I have been reading this afternoon and it seems that there are two primary ways of making each linear rail:
  • Monolithic Linear Regulator from someone like Linear Technology (eg. LT1086 (http://www.linear.com/product/LT1086) or LT1084 (http://www.linear.com/product/LT1084-Fixed)).  Decent noise and ripple rejection (PSSR), good transient response, simple implementation (I think), lower heat and quite cheap
  • Shunt + Opamp diy regulator in the style of something like Jung Didden and it's derivatives (http://sjostromaudio.com/pages/index.php/hifi-projects/176-ssr03-sjoestroem-super-regulator-power-supply).  Better ripple rejection, lower noise, not sure about transient response but larger, hotter and more expensive to build

Peter and Coen - is this an accurate summation of the two approaches to linear regulation?  Are there more approaches that I have not learned the existence of?

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 29, 2013, 08:34:17 am

The active cooling in the PC ? well, I guess you can put a ship's engine in there and it will still be cool enough. Sadly the fans will make more noise than that engine. Also I don't think that any overly dissipating (because actually too hot) will work at the somewhat higher ambient temperatures, let alone close to 30C/86F. Careful now because people from the hotter parts of the globe may think this will never happen because of air conditioners, but in countries like here we don't have them. We take it for granted that a couple of times per year we almost die of heat and we grab an extra cold beer. In the mean time 26C/79F is very normal during the better weather, and that anticipates cold amps or otherwise ...

So don't underestimate what happens once the heat can't be dissipated because of the somewhat higher ambient temperature. And this goes "exponential".
But yes, the case can have some for sure, but it won't be the way to do it. And, also "know" that no cold wind will cool a small surface efficiently. It really needs a heatsink of sufficient size. Think that metal-metal flows better, and that metal-air actually creates a protective film (little layer).

Lastly, supposed it will be 80C/176F in that PC case. I don't think it will be a problem, and for example the CPU will still be 40C/104F or whatever it originally was. Nothing will die of it and nothing will melt. One problem : nothing will last long either. So, if you look at the life ratings of capacitors, you will see that this is at 60C/140F and then they last 1 or 2 years, depending on the quality (but see spec). Make that 80/176 and in no-time they will be gone. Or, make it 40/104 and they will last forever.

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 29, 2013, 08:42:04 am
Quote
Peter and Coen - is this an accurate summation of the two approaches to linear regulation?  Are there more approaches that I have not learned the existence of?

What I have been thinking about for many times is just making as many PSU's from the ground up as needed. Hey, look in the left leg of your NOS1. Those ... :yes:

But ... I never knew the current needed per rail and such but we know that now. I didn't look it up in this topic, but I think max needed is 4A, right ?
Ok, that PSU can do 3A.

I am also not sure anymore whether -12V is needed but that can be done too. It just needs more of these ...

Also see next post.




Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 29, 2013, 08:43:38 am

Maybe here is another perspective; this is not new for me, and maybe especially because of that it could be part of the "design" :

Minimize the useage at the hardware side.

For example, I see that we are talking about support for SATA drives and such. But what if no single drive would be in there ? at least that is what I personally am aming for. Not so easy, but I will get it done.
Let's say that this decreases the usage with 6.5W, which is what I measured for a 3.5" spinning disk. So, little too much maybe, but maybe we can shut down a couple of other things because if this (anybody looked what SouthBridge actually does ? well, can probably not be shut off, but could use as much as the cpu).

What I also notice - and without knowing the real merit of this - is that by now I am using 1.5W less than reported earlier. Is my meter burning in ? :swoon:
So Idle is 51W now and playing is 53 - 55.5W.

Deduct that 6.5W and we have 49W left for playback.
Don't ask me about the needed headroom, but I think I can see 65W in shorter spikes, like when decoding FLAC. This will be 58.5W without the disk in there.
What I'm saying is that for shorter whiles things are allowed to heat up a bit and next we need safety for boot and maybe shut down.


So, never mind the real merits of this, I think it can always be useful. Also see next post. :)


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 29, 2013, 09:00:11 am

It's a bit of a trick, we might also blow something at attempting it, but I think this can work :

Create a capacitor bank for each rail;
I'm afraid it was a bit before your time here Anthony, so you won't have such a card : PCI supply rail noise  (http://www.phasure.com/index.php?topic=2551.0) (but many of us do). Anyway, almost the same principle I am talking about, and putting this in even might work (but I don't think so). Thus the basic idea :

Have that capacitor bank for each rail and anticipate a power outage of what ? 0.2 seconds ?
Connect your PSU (of whatever due kind) through it.
In parallel connect the normal ATX through it.
Never have switched on both at the same time, although I actually wonder what will really happen when so after all. But let's not do that.

Boot the PC through the normal ATX SPSU;
Runs ? then switch off that one and switch on the lower rated LPSU of which we know it can take all when things run and do it before the caps run empty. Runs empty too soon ? have more of them.

Want to shut down ? then go the other way around.

I probably make a mistake or two but at this moment I think this can work.
??
Peter



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 29, 2013, 09:05:01 am
Quote
but at this moment I think this can work.

And two minutes later I already think that we will be subject to the cap's "ripple" and that this won't be so noise-free.

... And when I write *that* I see myself again thinking that I still don't see much how a nice (electrical) noiseless supply in there will help audio SQ ...

... Which tells me that even additional noise from those caps is not a problem, while in the mean time the SPSU is still out of the way which *is* a problem to my belief (spitting into the mains).

Hmm ...


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 29, 2013, 09:18:46 am
Hey, look in the left leg of your NOS1. Those ... :yes:

Btw, output ripple of that is 0.5mV. FWIW, way less than that 120mV on the 12V and 50mV on the 5V/3.3V.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: CoenP on October 29, 2013, 09:38:44 am
Saying that, I have been reading this afternoon and it seems that there are two primary ways of making each linear rail:
  • Monolithic Linear Regulator from someone like Linear Technology (eg. LT1086 (http://www.linear.com/product/LT1086) or LT1084 (http://www.linear.com/product/LT1084-Fixed)).  Decent noise and ripple rejection (PSSR), good transient response, simple implementation (I think), lower heat and quite cheap
  • Shunt + Opamp diy regulator in the style of something like Jung Didden and it's derivatives (http://sjostromaudio.com/pages/index.php/hifi-projects/176-ssr03-sjoestroem-super-regulator-power-supply).  Better ripple rejection, lower noise, not sure about transient response but larger, hotter and more expensive to build

Peter and Coen - is this an accurate summation of the two approaches to linear regulation?  Are there more approaches that I have not learned the existence of?

Anthony

The lt series is only good for a few amperes of regulated current. That will do a HDD or a fan best. There are other more capable monolithic solutions. The datasheets also tell you how to boost the current with extra power BJTs. They are very low drop and available in the needed voltages.

I feel heat is still an issue. I know that you can get away with other constraints ie a lower ambient temperature, but as Peter said, component life expectancy progressively reduces with increasing remperature.
You also have to realise that most regulating solutions do NOT regulate transients or hf components. Actually the regulator may have an inductive output feeding oscillations.

The shuntreg is a worst case class A circuit, that is that is has to provide the peak current all the time, so if you need say at peak 2.5 Amps, the currentsource and sink have to both dissipate at least this 2.5 Amps. For a 12v currents sink alone this is 30Watts. Adding the source, you easily end up with a 40-50 Watt dissipation. You should save those for small signal audiocircuitry or ultra energy efficient PCs.

As they say on the silentpcreview site: a little air goes a long way. This is very true for the heatsinking of my cpu. When called for duty very little airflow can keep my megahalems cool compared to a hot touch  when absent. If you decide to go the powerdissipation route, you might consider previous generation cpu coolers as heatsink (to save some money). The are designed to get 100+ watts out of the CPU and keep it cool with a little air. As can be seen on the heatsink datasheets forced air can get small heatsinks to archieve 0.8deg/watt or lower.

As you will know most switching PSUs are not very efficient in the low wattage. If you measure the powerdraw on the AC side, the real powerdraw by the motherboard and components will be less so that helps a little.

I fully agree with minimising the powerrequirements for the PC first. This will make life much easier. I hope Peter will share some ideas on the "unconnected" PC he talked about before. Undervolting and undrclocking are a good start.

Regards, coen


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 29, 2013, 09:40:16 am
Awesome idea with the capacitor bank and the ATX supply to simply start the XXHE PC Peter and of course I have an idea or two in addition.

As mentioned earlier, I am sure that I can use a $2 chip and a small circuit board to do the ATX power on and off stuff.  One particular chip in mind can control two 12V lines (as well as a 5V, 3.3V, 5V SB, PS_ON etc.) which is important for this build.  I am sure that a little bit of additional logic can be included on that circuit board to also manage the supply that is to be used when the XXHE PC needs to boot or even on the occasions when the XXHE PC is not running in minimised o/s mode.

Wait for my next post...I will explain more...I have to put the kids to bed right now.

Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 29, 2013, 09:44:36 am
5V Rail

There are 5 5V pins on the P24 socket and each pin alone will power up the mobo if all the other 5V pins are not powered.  I cut all the 5v wires, twisted the mobo end of the cuts together into one joint, remove all but one cut 5V wire from the SMPS side of the cuts and made the measurements below...

o/s StateStartup      Idle      Music      Shutdown     
Maximised      4.0A2.2A2.2A to start, 2.0A stable      2.3A
Minimised4.1A2.2Astart 2.2A, stable 2.0A2.2A

Like the 12V rail, the 5V rail does not seem to be impacted by the sate of the o/s.  I am not confident that 4.0A peak during startup has been recorded accurately because it is displayed on the multimeter as a rapidly changing amperage which may mean that the peak has been missed.

Actually this 5V seems the only problem. Ok, see next post.
:)


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 29, 2013, 09:50:55 am
So ...

Anthony, since you are as far as you are with all the elementary requirements, why wouldn't this one be made for the job ?

http://www.velleman.eu/downloads/2/ps230210gbnlfresd.pdf

500-600 euros or so.
Does all we need and more. And major advantage : should be safe.
Will boot as well. Haha.

Is this now a bad idea for us hobbyists ?


PS: Side note : I can get these for a lower price. Not sure how that works out net with shipping and all.



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 29, 2013, 09:56:02 am
And to keep things going somewhat ...
Pedal, we have the parts for your PC so we could just as well try to "implement" this one with the great help of Anthony's schematics. Unless someone sees something wrong with it.

So I think I am serious on this Lab PSU and now I need the help of you out there seeing something wrong with it.

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 29, 2013, 10:04:36 am
The main issues that I have with a lab supply like that for a final solution Peter are noise (the bigger output lab linears are all fan cooled as far as I know) and knobs (and how kids love to tweak them).  Plus, I think their implementation will not be as good as something we build especially for it.

I could not read the manual for that supply Peter...wrong language for me.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 29, 2013, 10:09:30 am
Hmm ... First part of that manual seems English to me ?

But there's another downside so far : No 115V as it seems.

About the fan(s), yes, you could be right.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 29, 2013, 10:28:08 am
Based on Peters forward thinking regarding the capacitor bank and the ATX psu to start up and shut down the pc, following are my ideas on a clean implementation.

As mentioned earlier, I am sure that I can use a $2 chip to make a small circuit board to control the linear power rails and motherboard to full ATX power specification.  Peter has said that he has some decent linear regulators used in the NOS1 that can go to 3A output (is this maximum output Peter, or continuous output?).  There are two rails that we will have an issue with needing more than 3A of current:  the 12v P8 socket which will need at least 5A, preferably more during startup and shutdown; and the 5V rail into the P24 socket which will need about 5A at shutdown.  The remainder of the rails can be serviced by a 3A or smaller supply.

So, the only time that we should need more current is during startup and shutdown...which I should be able to identify by the voltage on the 'PWR_ON' leg of the aforementioned $2 chip (each state has a seperate voltage range).  So I propose one power switch and one toggle...the toggle to tell us that we want the linear ATX PSU to go into "Extreme Low Power Mode" because the XXHE PC is optimised and ready to roll in low voltage mode...the power switch to simply turn on and off the pc.

When the toggle is NOT set for "Extreme Low Power Mode" my little circuit board will boot on the pc using the normal voltage rails and a special low spec, low cost 12V 5A+ and 5V 5A+ as well as the normal high performance rails for everything else.  I can use cheap monolithic 7.5A or 10A LT regulators and use a dual wound transformer for thes 'high power' rails.

When the computer restarts with the toggle in "Extreme Low Power Mode" the circuit board will still start the XXHE PC as mentioned in the previous paragraph, but once it is booted it will use the capacitor bank and turn off the high amp/low spec rails and turn on the low amp/high performance 5V and 12V rails.  Likewise, when a shutdown is triggered, the mobo will let the $2 chip know what is going on and it will use the capacitor bank to turn off the two low amperage rails and turn on the high amperage rails for shutdown.

I think I can implement this.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 29, 2013, 10:50:51 am

The lt series is only good for a few amperes of regulated current. That will do a HDD or a fan best. There are other more capable monolithic solutions. The datasheets also tell you how to boost the current with extra power BJTs. They are very low drop and available in the needed voltages.

Thanks Coen.  The LT1083 will do 7.5A with 5V and 12V.  They cost about AU$20 each over here.  That may be a decent solution for the two high amp/low spec. rails I mentioned in my previous post.  I would love to hear your other suggestions though...I only had a look this afternoon and these were the best I could find.

I feel heat is still an issue. I know that you can get away with other constraints ie a lower ambient temperature, but as Peter said, component life expectancy progressively reduces with increasing remperature.
You also have to realise that most regulating solutions do NOT regulate transients or hf components. Actually the regulator may have an inductive output feeding oscillations.

The shuntreg is a worst case class A circuit, that is that is has to provide the peak current all the time, so if you need say at peak 2.5 Amps, the currentsource and sink have to both dissipate at least this 2.5 Amps. For a 12v currents sink alone this is 30Watts. Adding the source, you easily end up with a 40-50 Watt dissipation. You should save those for small signal audiocircuitry or ultra energy efficient PCs.

As they say on the silentpcreview site: a little air goes a long way. This is very true for the heatsinking of my cpu. When called for duty very little airflow can keep my megahalems cool compared to a hot touch  when absent. If you decide to go the powerdissipation route, you might consider previous generation cpu coolers as heatsink (to save some money). The are designed to get 100+ watts out of the CPU and keep it cool with a little air. As can be seen on the heatsink datasheets forced air can get small heatsinks to archieve 0.8deg/watt or lower.


To be honest I have not looked into heat too much at all.  An aluminium case with plenty of mass and decent heat-sinking can be VERY expensive to get made (unless there are suitable mass-produced amp cases on the market - now that's an idea) but I would love to make the entire XXHE PC passively cooled, but that may not be feasible if we want the components to last.

Thank again Coen.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 29, 2013, 10:52:48 am
Quote
Peter has said that he has some decent linear regulators used in the NOS1 that can go to 3A output

Small correction : Peter said that another option was to have separate LPSU's for each rail and that one of those is in the NOS1's left leg. So this is no regulator but a whole PSU.
(and yes, that 3A should be for continuous use, though I never tried that)

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 29, 2013, 11:32:32 am
Quote
Peter has said that he has some decent linear regulators used in the NOS1 that can go to 3A output

Small correction : Peter said that another option was to have separate LPSU's for each rail and that one of those is in the NOS1's left leg. So this is no regulator but a whole PSU.
(and yes, that 3A should be for continuous use, though I never tried that)

Peter

Even better Peter.  I was of the opinion that best practice would probably be a separate psu for each rail.  Sounds like it may save some development time also.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: CoenP on October 29, 2013, 12:27:19 pm
I found the nice LDO regulators in my archive. The typenumber(s) is:

Micrel MC29750 to 29753.

 "Only" 7.5 amps but very nice specs. A few of these should do a music PC. Only0.5V dropout so you can keep input voltage close to the desired voltage (under minimum volt line condition).
There is also a nice LDO design section in the datasheets that covers most implementation aspects of safe operation.

I once thought of these to reduce the ripple of a normal switching supply. That is: readjust the ATX voltages to a minimum 0.6v overvoltage (under load) and kill the ripple with these LDO babies.

Intriguingly the Velleman labsupply has an "operation" of 8 hours....
Undoubtably this is about the heat building up.

Regards, coen


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 29, 2013, 12:33:10 pm
Quote
Intriguingly the Velleman labsupply has an "operation" of 8 hours....
Undoubtably this is about the heat building up.

Haha, I saw that too. But no, that would be non-sense. I merely read it in the realm of "with this you can finish your working day" (no breaks :swoon:).

Peter


PS: But of course no heat builds up "more" after the 8th hour of operation.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: CoenP on October 29, 2013, 12:40:50 pm
Quote
Intriguingly the Velleman labsupply has an "operation" of 8 hours....
Undoubtably this is about the heat building up.

Haha, I saw that too. But no, that would be non-sense. I merely read it in the realm of "with this you can finish your working day" (no breaks :swoon:).

Peter


PS: But of course no heat builds up "more" after the 8th hour of operation.

Ok, you're right  no heat capaticance that keeps charging for 8 hours in such a small casing. But is remains an odd statement to me and will probably have to do with the lifespan/guarantee at serious lab loading (hence heat).

Regards,  Coen


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 29, 2013, 01:05:06 pm
I found the nice LDO regulators in my archive. The typenumber(s) is:

Micrel MC29750 to 29753.

 "Only" 7.5 amps but very nice specs. A few of these should do a music PC. Only0.5V dropout so you can keep input voltage close to the desired voltage (under minimum volt line condition).
There is also a nice LDO design section in the datasheets that covers most implementation aspects of safe operation.

I once thought of these to reduce the ripple of a normal switching supply. That is: readjust the ATX voltages to a minimum 0.6v overvoltage (under load) and kill the ripple with these LDO babies.


Thanks Coen.  I looked these up but their noise was rather high at about 260uV and no PSRR figures.  I am reading the specs differently to you...but that 25 page spec. sheet very helpful.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: Arjan on October 29, 2013, 03:30:35 pm
Hi,
I am reading this interesting discussion. I am not an expert!! but here are my ideas:

I will use 2 simple adjustable supplies (PEAKTECH-6080) for the audio grade usb3 card 5V and HDD (via esata) 5V and 12V. I already ordered this.

Will try later a picoPSU 160 XT with following fixed output supply, EA Elektro-Automatik EA-PS 2012-15 (12V 15A).

Question will this picoPSU work on the XXHighend PC? If not, possible solution: Leave the standard ATX supply on the 24pins and use the picoPSU to feed only the CPU and fans?

regards, Arjan


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 29, 2013, 11:28:14 pm
Hi,
I am reading this interesting discussion. I am not an expert!! but here are my ideas:

I will use 2 simple adjustable supplies (PEAKTECH-6080) for the audio grade usb3 card 5V and HDD (via esata) 5V and 12V. I already ordered this.

Will try later a picoPSU 160 XT with following fixed output supply, EA Elektro-Automatik EA-PS 2012-15 (12V 15A).

Question will this picoPSU work on the XXHighend PC? If not, possible solution: Leave the standard ATX supply on the 24pins and use the picoPSU to feed only the CPU and fans?

regards, Arjan

Hi Arjan,

One of the things that has not yet been explicitly stated in this thread, but I suppose I am doing it now, is that one of the design goals is to have the computer managed by a single well designed power source.  As things are looking now this power source will actually be a number of smaller linear power supplies within the one 'box' that can be managed as a single unit.  This may improve grounding issues and it will certainly improve usability and computer life.  With a 'one box' solution we don't have multiple power supplies of possibly dubious construction feeding hash back into the mains (just one...haha) and the computer can be managed as it is used to being managed and hence its lifespan will be extended. 

I would not be surprised if much of the gains made by this psu were because of the reduction of hash feeding back into the mains to impact other components.  I am sure there will be gains by improving the USB card performance and we will have to wait and see on the other rails.

I don't know if a 160w pico will start up the standard XXHE PC that Peter makes, but there is no need for the picoPSU now because we can build our own version of it without the noisy switching supplies onboard, which should give a better result. 

Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: CoenP on October 29, 2013, 11:38:45 pm
I found the nice LDO regulators in my archive. The typenumber(s) is:

Micrel MC29750 to 29753.

 "Only" 7.5 amps but very nice specs. A few of these should do a music PC. Only0.5V dropout so you can keep input voltage close to the desired voltage (under minimum volt line condition).
There is also a nice LDO design section in the datasheets that covers most implementation aspects of safe operation.

I once thought of these to reduce the ripple of a normal switching supply. That is: readjust the ATX voltages to a minimum 0.6v overvoltage (under load) and kill the ripple with these LDO babies.


Thanks Coen.  I looked these up but their noise was rather high at about 260uV and no PSRR figures.  I am reading the specs differently to you...but that 25 page spec. sheet very helpful.

Anthony
Arjan,

Which picopsu do you intend to use? I wonder if any of them is fit for being a xxhe supply.

As Anthony posted before a pc supply has to conform to the ATX standard for a board to start and function properly. This is about having voltages within the specs before supplying them to the mobo. You get yourself into trouble if you use two (or more) supplies. Who is doing the powermanagement?

So what may work is one supply for the mobo 24 and 4/6 pin connectors and one more for the periferals (fans hdds etc.). You have to orchestrate the power up and make shure the sata hdds etc have power to be recognised by the BIOS.

Regards, coen


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: CoenP on October 29, 2013, 11:50:04 pm
Thanks Coen.  I looked these up but their noise was rather high at about 260uV and no PSRR figures.  I am reading the specs differently to you...but that 25 page spec. sheet very helpful.

Anthony

That noise figure may turn out to be important or not, but I see other problem areas that need much more attention and are more likely to correlate with "better" sound.
Nevertheless the LT1083 also looks impressive, they have a price for a reason. There is also a 15xx series that raises my interest.

Warning/Teaser: If you converge on your regulation setup the next challenge will be a healthy supply and groundingplan. This will make or break all the hard regulation work. Next to theory and opinions it will reqiure practical experiments to find out whats best.

Regards, Coen


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: Arjan on October 30, 2013, 12:26:19 am
Hi Coen,

I saw a picoPsu on the same site were the audiograde usb3 comes from.
It is Max. 160 - 168 watt. Why are these picoPsu's so limited?

Yes, a one box solution is the best. The idea of splitting the pin24 and CPU power was just my 'out of the box' thinking. But as stated before I am not an expert. So I totally missed the power management issue.

Regards, Arjan


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 30, 2013, 12:42:37 am
Warning/Teaser: If you converge on your regulation setup the next challenge will be a healthy supply and groundingplan. This will make or break all the hard regulation work. Next to theory and opinions it will reqiure practical experiments to find out whats best.


Yes...the grounding...has me a little worried as well.  When I put four rails into the motherboard and 'tricked' the XXHE PC into starting up without the ATX procedure I may or may not have been lucky with the grounding of the separate pins on the P24 socket (the P8 socket may not be so bad because it has a single 12V rail and its own dedicated grounding wires).  The P24 socket has a number of ground wires but there is no mention of grounding in the ATX power specifications, so I have no idea which ground wire/s needs to be paired with which positive wire/s let alone which rails.  I suspect that it may not matter so much because of one simple observation that I have made...that each of the three main power rails into the P24 socket (3.3V/5V/12V) has multiple wires in the connector, but the computer will post/boot/play music with ANY single one of them powered, which indicates to me not only that the multiple wires for each rail are connected on the mobo side of the P24 socket, but that the grounds are connected also, because if the grounds were not connected current would not flow and the computer would not run.

The grounding issue then becomes less a 'within the individual wires of each rail' problem and more a 'between the separate rails' concern which thankfully may be much easier to test/tweak/solve.  The fact that I randomly chose which ground wires within the P24 socket to pair with each rail of power fed into that socket and I got it to work first go suggests that it is not necessarily a major issue in getting the motherboard to function, but I agree that some noise measurements would be useful to determine if changing the grounding pins to each rail affects performance.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 30, 2013, 12:48:18 am
Hi Coen,

I saw a picoPsu on the same site were the audiograde usb3 comes from.
It is Max. 160 - 168 watt. Why are these picoPsu's so limited?

Yes, a one box solution is the best. The idea of splitting the pin24 and CPU power was just my 'out of the box' thinking. But as stated before I am not an expert. So I totally missed the power management issue.

Regards, Arjan

Hi Arjan,

Yes Paul Pang does offer a modified wide input picoPSU type of dc-dc converter (not sure that it is the picoPSU brand) to which he has grafted higher quality wire.

Your thinking was not far off what several people at the moment do with the P24 socket which is something I suggested at the JPlay forum: power up the pc with a picoPSU and then use a couple of relays to switch to linear on those rails when the pc has booted.  There are plenty of problems with that approach but it does work in a fashion and the guys doing it do report positive results.  Up until the last week I had no idea how to implement the ATX startup logic in a bespoke psu...but now that I do know how to do this we can get rid of the picoPSU and the ATX SMPS.

Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 30, 2013, 01:56:57 am

For example, I see that we are talking about support for SATA drives and such. But what if no single drive would be in there ? at least that is what I personally am aming for. Not so easy, but I will get it done.


Peter, do you care to elaborate how you intend to get away without a single drive in the XXHE PC?  Are you trying to run the o/s from an external drive?  Maybe load the o/s onto a ram disk?  If that can even be done.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 30, 2013, 02:48:38 am
NUMBER OF RAILS

Another thing to think about is the number of rails that the supply will require to operate the pc.

A special consideration is the 5V Standby pin on the ATX power supply.  The ATX power scheduling requires the 5V Standby line to be powered whenever the AC is turned on in the power supply.  This rail is operated by the little switch that you find on every ATX SMPS.  Turn it on and the 5V Standby rail becomes active and some of the circuits in the motherboard are powered.  The Asrock X79 Extreme4-M motherboard that is standard (and highly recommended) in the XXHE PC will draw no more than 1A from the 5V Standby rail, but the ATX power specifications suggest that 2A be made available to suit future motherboard features (at present this powers the front power button on your pc case, wake-on-lan, wake-on-usb etc).  Do we provide 2A to this rail or just 1A?  A 1A rail is easier and cheaper to build.  This rail must be powered BEFORE any of the other rails.

Now, it may just be the case that running the maximum possible number of rails into the XXHE PC produces the best results.  But it may also be the case that we can combine some of these rails to make the final product that Peter will produce (I think that is what will happen) less expensive and better bang for the buck.

Maximum number of rails that can be fed into the XXHE PC:
#1 5V Standby line
#2 P8 12V 6A
#3 SSD 5V 2A
#4 PPAstudio USB Card - ultra high quality 5v 0.2A feed
#5 P24 3.3V 3A
#6 P24 5V 5A
#7 P24 12V 2A
#8 Fans 5v 0.5A

Minimum number of rails that can be run into the XXHE PC:
#1 5V 9A for Standby line, SSD, PPAstudio USB card, P24, fans
#2 12V 8A for P8 and P24
#3 3.3V 3A for P24

I do not think that 3 rails can work well.  Firstly, the PPAstudio USB card will be quite responsive to an ultra high quality power supply and we are just not going to get that with 9A on that rail.  Secondly, the 5V Standby will generate a lot of heat (up to 45W) and will use plenty of power if the switch on the back of the linear power supply is not turned off when the PC is not in use.  Thirdly, we may find it beneficial to run the fans on a separate rail to get rid of the electrical noise messing with other 5V components.  Fourthly, I would be a little surprised if powering the cpu separately did not provide some advantage to the entire computer, considering much of the electronic noise probably comes from there already.

So I guess that I am saying the XXHE PC LPSU will probably end up with somewhere between 6 and 8 separate rails. 

I suppose a further contentious point is the inclusion of the PPAstudio USB card in the XXHE PC build.  A couple of us have tried it now and it seems to work well: maybe we should get others to try it also and give their opinion.  The one to convince though is Peter.  Are you tempted to try one of those cards Peter?

Cheers,

Anthony




Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 30, 2013, 10:24:20 am
Warning/Teaser: If you converge on your regulation setup the next challenge will be a healthy supply and groundingplan. This will make or break all the hard regulation work. Next to theory and opinions it will reqiure practical experiments to find out whats best.


Yes...the grounding...has me a little worried as well.  When I put four rails into the motherboard and 'tricked' the XXHE PC into starting up without the ATX procedure I may or may not have been lucky with the grounding of the separate pins on the P24 socket (the P8 socket may not be so bad because it has a single 12V rail and its own dedicated grounding wires).  

Anthony,

This is not (so much) about properly grounding some wires and certainly not those carrying 220mV of noise to begin with. It is about the maybe achievable 220uV of noise from these regulators and how this needs the most careful groundplanes (in layered boards) in order to not make it 220mV again right from the start. And to be honest, I don't think this can be done. Oh, there can be this well designed PCB all right, but then what ? it/they will sit at a mile distance of where the voltage is needed and any regulator board neatly coughing up 220uV will show 1mV at the end where the voltage is needed.

The 1mV I make up for a reason and actually I have no idea. The 220uV was also made up, and as far as I have seen so far it will merely be in the 300uV range for 7A or 9A regulators. Also they must stay very cool in order to meet their power requierments and I am not so sure whether this "very cool" can be achieved in there.

The reason for coming up with 1mV is because that can be achieved fairly easy with a LPSU. So, what to do difficult for behind that PSU when it won't get better anyway. Or worse.

Also ... Then we entered the mother board. All sorts of sh*t happens there and although all will be made to spec (to run well), nobody is going to tell me that anything good will be happening there when the base for all MoBo designers is 220mV of noise to begin with. And oh, on-board regulators may make that better but the point is that this is out of our control anyway. So for example, who tells that there is no 12V regulator on the already 12V rail just to eliminate the expected (sure high) 220mV ? (easy to check at the consumer side where it should show less than 12V in that case). But what I mean is that such a regulator will have an inherent (say) 10mV of noise and there you go.

Or what about other regulators spitting on the same ground (assumed no low noise design for that on the MoBo) ?

I (now) say it is all completely useless to try to improve upon ~1mV of noise coming from the PSU;
This regulator subject sort of started its own life, while (I think) I proposed it as that other means to provide better (less-noise) power. But on its own useless again because it merely should be about (the SPSU) not spitting into the mains.

And hey, before we think all is arranged for regarding that spitting, we better connect our monitors to such a LPSU as well.

But correct me where you can please !
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 30, 2013, 10:36:27 am
Quote
author=PeterSt link=topic=2726.msg28752#msg28752

And hey, before we think all is arranged for regarding that spitting, we better connect our monitors to such a LPSU as well.

My monitors are run on a separate circuit to the audio gear (which includes the XXHE PC) which has its own dedicated circuit.

We would need a big LPSU for a monitor...mine draws about 70w in general use, but I've never measured it at startup.

How vibrant would the colours be!!!!  haha :grazy:


Title: Isolating transformer might help?
Post by: BertD on October 30, 2013, 10:38:24 am
And hey, before we think all is arranged for regarding that spitting, we better connect our monitors to such a LPSU as well.

Isolating transformer? Connect all noisy spitting stuff at the isolated end?


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 30, 2013, 10:42:40 am

A just-not different subject :

For a longer time I have been thinking to produce this small box with such a LPSU in it for any device we just *need* around the audio rack and assumed no separately earthed mains ring is available for that. It's probably only that I do have these separate rings why I didn't make a bunch for myself.

For example think about all the self-powered USB devices we may use. All could be powered from this one little box.

One problem I foresee at this moment : how to make general "adapting" inlets so all devices can go in there (I am not talking about the different voltages). Also, not all devices have detachable cords hence those cords must be cut and some new connector must be soldered on it. ... And next it can't be used elsewhere anymore.

Let's not proceed with this subject in this topic, but I only wanted to make clear what we are actually working on, and how that is related to more, or otherwise it is a useless endeavor.

Regards,
Peter


PS: Saw the bottom of my sig ? - yea yea, I know. There's one left - in the PC ... ;)


Title: Re: Isolating transformer might help?
Post by: PeterSt on October 30, 2013, 10:47:54 am
And hey, before we think all is arranged for regarding that spitting, we better connect our monitors to such a LPSU as well.

Isolating transformer? Connect all noisy spitting stuff at the isolated end?

Hey Bert - Do you mean such a beast like e.g. Mani has ?


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 30, 2013, 10:51:53 am
Quote
My monitors are run on a separate circuit to the audio gear (which includes the XXHE PC) which has its own dedicated circuit.

And then to think that I scratched this subject from my post (after yours Anthony). :offtopic: :secret:

But if you really have those rings separately earthed, measure the voltage over the two earths. Just for fun.
So this is what I do *not* do (PC is in the audio ring).

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 30, 2013, 10:54:35 am
My PC is on the dedicated audio circuit (dedicate from the mains box)...my monitors are on another circuit for the other computers.  No separate ground for audio...I'm pretty sure that's illegal here.


Title: Re: Isolating transformer might help?
Post by: BertD on October 30, 2013, 10:57:30 am

Hey Bert - Do you mean such a beast like e.g. Mani has ?


Something like that but smaller will do as well as long as you do not connect all your PC's to that one transformer... ;-)

I am using a 1000VA for both my PC's (and related switching adapters), one monitor and one Behringer.

http://www.amplimo.com/index.php/products/safety-transformers-for-medical-use

Bert


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 30, 2013, 11:11:04 am

Anthony,

This is not (so much) about properly grounding some wires and certainly not those carrying 220mV of noise to begin with. It is about the maybe achievable 220uV of noise from these regulators and how this needs the most careful groundplanes (in layered boards) in order to not make it 220mV again right from the start. And to be honest, I don't think this can be done. Oh, there can be this well designed PCB all right, but then what ? it/they will sit at a mile distance of where the voltage is needed and any regulator board neatly coughing up 220uV will show 1mV at the end where the voltage is needed.

The 1mV I make up for a reason and actually I have no idea. The 220uV was also made up, and as far as I have seen so far it will merely be in the 300uV range for 7A or 9A regulators. Also they must stay very cool in order to meet their power requierments and I am not so sure whether this "very cool" can be achieved in there.

The reason for coming up with 1mV is because that can be achieved fairly easy with a LPSU. So, what to do difficult for behind that PSU when it won't get better anyway. Or worse.

Also ... Then we entered the mother board. All sorts of sh*t happens there and although all will be made to spec (to run well), nobody is going to tell me that anything good will be happening there when the base for all MoBo designers is 220mV of noise to begin with. And oh, on-board regulators may make that better but the point is that this is out of our control anyway. So for example, who tells that there is no 12V regulator on the already 12V rail just to eliminate the expected (sure high) 220mV ? (easy to check at the consumer side where it should show less than 12V in that case). But what I mean is that such a regulator will have an inherent (say) 10mV of noise and there you go.

Or what about other regulators spitting on the same ground (assumed no low noise design for that on the MoBo) ?

I (now) say it is all completely useless to try to improve upon ~1mV of noise coming from the PSU;
This regulator subject sort of started its own life, while (I think) I proposed it as that other means to provide better (less-noise) power. But on its own useless again because it merely should be about (the SPSU) not spitting into the mains.

And hey, before we think all is arranged for regarding that spitting, we better connect our monitors to such a LPSU as well.

But correct me where you can please !
Peter


At the moment any gains/losses in sq from this linear psu project are theoretical and speculative at best.  We just don't know, and as you said early in this thread this is a VERY complicated area.  

I know of one respected audio engineer with good products (that I have owned) that was convinced by his clients to try a simple single rail linear power supply into his computer.  Eventually he gave in, put together a good one with a Hynes reg and could not figure out why power supply made such a difference in his system as it had in his clients systems.  No real explanation...it just worked above and beyond the "hash into the mains" theory.  Adding a LPSU to the USB card that I have in my computer ratchets up SQ in my system.  Why?  I don't really know but it may be something to do with grounding or noise on the USB cable or even placebo.  I've tried it a few times now just for a sanity check and I get the same result every time.

Anyway, the reason I have started this thread is because I want to know what will happen if I put high quality linear power into everything and learn which components benefit from that power.  If we can get away with two or three rails that would be awesome and relatively inexpensive, but if we don't try we won't know for sure.

Anthony  


Title: Re: Isolating transformer might help?
Post by: acg on October 30, 2013, 11:14:55 am

Hey Bert - Do you mean such a beast like e.g. Mani has ?


Something like that but smaller will do as well as long as you do not connect all your PC's to that one transformer... ;-)

I am using a 1000VA for both my PC's (and related switching adapters), one monitor and one Behringer.

http://www.amplimo.com/index.php/products/safety-transformers-for-medical-use

Bert


There is a good thread (http://www.stereo.net.au/forums/index.php?/topic/57548-power-conditioner-shootout-psaudio-vs-ag1500-vs-airlink-balanced-power-supply/) going on these things over on my local forum at the moment.  A product made in the UK has fared very well in the value for money stakes.

Anthony


Title: Re: Isolating transformer might help?
Post by: BertD on October 30, 2013, 11:17:54 am
http://www.amplimo.com/index.php/products/safety-transformers-for-medical-use

BTW, never use these type transformers to connect your amplifiers too. It is tempting but it makes the sound dull...

...unless it is a HUGE one. ;-)

Just use it to keep your own mains clean(er) by not adding.

NOTE The internal earth shield is one very effective part of this transformer...


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 30, 2013, 12:15:03 pm
Now let me see ...

So with my good senses (which may be worth nothing in the first place) I say that this is all about spitting back in the mains. So, I get myself such a transformer plus a couple of fuses and resistors plus some sort of cabinet and my issue of concern is solved ?

Hmm ...



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 30, 2013, 01:00:33 pm
Ignorant me again ...

So, can anyone tell me how such an "isolation" transformer would isolate any back fired spikes and such ?
IOW I don't believe that.

I am not sure at all how that would work from the secundary to the primary but from the primary to the secundary it would work no different than a TVC for example, or any transformer based attenuator. And that such a transformer lets true all the AC it is fed with is a good thing for our audio. 8)

Maybe in this case (secundary the same voltage as the primary) the whole thing can even be connected the other way around (but not sure here). If that is so it tells enough already.

So ?


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: BertD on October 30, 2013, 01:33:55 pm
So, can anyone tell me how such an "isolation" transformer would isolate any back fired spikes and such ?
IOW I don't believe that.

It removes spikes generated by switches (transformer connected to isolate the audio equipment) so something get's lost in there! ;-)

Bert


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: BertD on October 30, 2013, 01:54:11 pm
Now let me see ...

So with my good senses (which may be worth nothing in the first place) I say that this is all about spitting back in the mains. So, I get myself such a transformer plus a couple of fuses and resistors plus some sort of cabinet and my issue of concern is solved ?

Hmm ...


I can take it with me next time I visit? Easy to take out and for you easy to measure the "differences"?

Connect a PC and "see" what happens at both ends of the transformer?

Bert


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 30, 2013, 02:45:09 pm
Bert, great idea.
Peter


PS: All I can think of is that high transient spikes (or very high frequencies) won't come through so easy just because a transformer is not fast enough.
But might you have referred to general "switching" (like from light switches or anything) now not being audible anymore - I don't think so. This is all ground loop stuff or lack thereof (remember our dishwasher story while one of the XLR pins was not connected ?).



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: BertD on October 30, 2013, 02:52:24 pm
But might you have referred to general "switching" (like from light switches or anything) now not being audible anymore - I don't think so. This is all ground loop stuff or lack thereof (remember our dishwasher story while one of the XLR pins was not connected ?).

It always made noise when I turned on the big light in my room (12 TL tubes). The moment the transformer was connected in "series" that noise stopped.

Perhaps more things were changed at the same time (that's me!) but that noise was gone.

The dishwasher was just having NO ground at all (floating) and that is acting as one major antenna picking up things out of the air, not the mains.

We will figure it out soon enough...


Title: Re: Isolating transformer might help?
Post by: Nick on October 30, 2013, 03:53:26 pm
There is a good thread (http://www.stereo.net.au/forums/index.php?/topic/57548-power-conditioner-shootout-psaudio-vs-ag1500-vs-airlink-balanced-power-supply/) going on these things over on my local forum at the moment.  A product made in the UK has fared very well in the value for money stakes.

There are a few members using the AirLink balanced transformers and more experiances in a thread on the forum.

I have ended up with couple of 3kva AirLink balanced transformers (as tested in the link above). They do make a really significant difference to sound quality and I generally agree with the tests findings on the AirLink. Paul and Mani also use them although I think Mani has 2X 5kva model IIRC. One thing that is worth bearing in mind and possibly not covered by the test is that the sound quality improvements are pretty much doubled (subjectively) if a dedicated audio system PE is setup with the AirLinks using an earth spike.

I also have some 2KVA single ended mains isolation transformers but compared to the AirLinks these are nowhere near so effective so I think a the balanced isolation transformer design is really worth the effort and cost.

The two 3kv AirLinks transformers power all of my audio system. PC, DAC and Gainclone amps are plugged into first AirLink and my active Subwoofers are plugged into the second AirLink. Placing the subs on their own AirLink makes a big difference. I agree with Berts view (below) that placing the "main amps" on the same isolation transformer as the rest of the audio system make a dull sound. This in the end was the reason for buying the second AirLink unit.

Its interesting that to obtain the best sound, I need to have my PC DAC and Gaincline amp plugged into the same AirLink unit. This seems to suggest that a common mains power reference point for these components is more important than the possible negative effects of hash being put back into the mains supply by the PC, DAC and Amps.

As you can tell I'm a big fan of the AirLinks  :).

Cheers,


Title: Surprised - Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: Scroobius on November 01, 2013, 09:45:15 pm

I have been using the AUDIO GRADE USB 3.0 PCIE CARD powered from the 5v supply from my PC Seasonic power supply. The performance is just superb (what? don't tell me that you haven't ordered one yet) it is fundamental in the performance of my system now.

Anyway how can such a fine piece of kit (the PCie card that is) sound any good powered by a switched mode PS?. So I got hold of a 5v linear power supply. The spec of it look promising (ripple 5mv) not that that means anything without looking at it with a scope. Anyway I hooked up the linear supply to my AUDIO GRADE USB 3.0 PCIE CARD - and sat back in amazement. It just did not sound right - a glassy edge (jitter?) returned to the music - the beautiful flowing detail had gone. So I went back to the SMPS - much better back to the beautiful flowing detail again.

I have to say that was a surprise I expected maybe the same(ish) or slightly better but not worse. I am going to have to have a look at what is going on with a scope.

Maybe the supply needs running in but it has a long way to go get to be even as good as let alone better than the SMPS.

I will try powering the clock with 3.3V battery power - but I will have to tear myself away from listening to music first so not top priority just now. Maybe when I go to see Nick again later this month.

Odd!!!

Paul


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on November 01, 2013, 10:56:12 pm
Paul, I _think_ that noise is more important than ripple for a USB card, which when you think about it the entire reason to use that USB card is to reduce noise making its way along the USB cable.  Not all linears are created equal, which may be why the modder of that card recommends a battery supply...but I am hoping that I (well Peter probably) can produce a definitive very low noise supply for that card.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on November 04, 2013, 07:20:16 pm
I merged the discussion about this PCI USB card (and source of noise to counteract) to here : Re: Great PC Tweak - A Bert "Must Have" (http://www.phasure.com/index.php?topic=2749.msg28778#msg28778).

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: Scroobius on November 04, 2013, 07:44:33 pm
Hi Anthony - I understand and agree about the noise aspect and I think Nick's previous posting about it points clearly in that direction but as I had a linear supply to hand I thought it would be worth a try as it only took a few minutes to set up. Well it should have only taken a few minutes if I had not corrupted my BIOS doing it  :(

Always good to see more than one "Nosser" getting the same results.

Cheers

Paul



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on November 10, 2013, 10:03:15 am
FYI : Windows 8.1 consumes 2.5W more everywhere (idle, playback etc.). I don't see how yet (cpu usage etc.) but it really does. Checked MinOS only.

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on November 10, 2013, 10:24:40 am
Anthony, I have a small question for you :

The other day I was watching the usage meter when Windows 8 was idle (no playback going on) and saw a usage of 4 Watts. I am not sure anymore how it fluctuated but anyway it did and the meter was just alive. This was for a shorter while like 10 seconds. Then it went back to normal.

Did you see anything like this ? At the time I thought it was possibly a fault of the meter and I didn't pay further attention to it. Saw that only once.

Yesterday, a while after I installed Windows 8.1 and being in MinOS (I think for the first time), I saw it again. This time I watched closely, and usage showed 4W as te base but it could jump to 7W or 9W. I was looking at this for maybe 45 seconds before I went elsewhere (or did something to the PC - could be playback) and after that never saw it again (once in a while looking).

I don't think it can be true anyway, unless you have seen similar ...

My PC never hybernates or anything and monitor is always on (for OS settings). The only disk in there (OS disk) can spin down (also during playback) but it would be very coincidental like once per hour it may for a few seconds. So it could be that situation (because rare and hard to catch) but then it would imply (much) more going down (using 46-48W less suddenly ?).

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on November 10, 2013, 11:10:48 am
Hi Peter,

I have not seen anything like that but when I was measuring the draw of the entire pc my accuracy was only about 10w.  When measuring the individual components the accuracy was much better and equal to the accuracy of the multimeter. 

Some of the individual components did seem to have non-rhythmic power usage, but my thought is that perhaps the culprit may be something like the fan controllers.  Maybe try to run the fans from another power source and disconnected from motherboard monitoring and control, just to see what happens.  That is the most immediate thing that I can think of that might have sporadic use of resources and low power draw.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on November 17, 2013, 04:06:41 pm
Anthony,

I just wanted to share this in this topic of the PSU : Something more to shut off ... USB3 (http://www.phasure.com/index.php?topic=2768.0).

It may be prior to your ages at our forum here, but notice that USB2 can be shut off in your XXHighEnd PC. And today I went one step further and did the same for USB3.

The net result on the total draw is something like 2-2.5 Wats less.
So notice that I first added the PCIe card which will draw something (I forgot to look) and that next USB2 was shut off. This makes this difference. After shutting off USB3 I saw no further decrease in usage. Not sure why.

Idle usage is 48.5 Watts now (MinOS) but I see similar in Normal OS ?? (Windows 8.1 !)
Playback (MinOS) goes from 49.0W to 55.0W which difference feels more than it was (was 3.5W or so, now 6W). This too could be W8.1 related and I dedicate the difference itself to SFS loads and not to USB usage (looking at the slow frequency of the usage difference).

It is a bit tricky to observe right, because in native W8 the idle usage was 50W while with W8.1 this is 51.5 - 52 (so now decreased to 48.5).

Only thing in there is one 2.5" spinning disk and otherwise the NOS1 is connected and a LAN cable (software wise shut off during playback).

Regards,
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on November 17, 2013, 07:18:27 pm
Variation without the card during playback is 3W. But it really needs waiting for the lowest and highest ends to get that. Looking "normally" for 10 secs or so (well capturing the SFS loads) it's only 2.5W.

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on November 20, 2013, 12:20:26 pm
FWIW by now (because I don't like W8.1 at all) :

W8.1 stops right away after shut down.
(remember, Native W8 may take over 20 seconds for this after the screen goes black)

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on November 20, 2013, 12:32:52 pm
Thanks Peter,

The atx power solution I have been working on should manage the shutdown process properly by intercommunication between the power supply and the mobo.  I say should, because I don't have a working prototype just yet...

Anthony


Title: Strange power usage behavior
Post by: PeterSt on November 29, 2013, 09:11:53 am
Hi,

This is just to share something I noticed and I think not of importance anywhere, at least not related to the XXHighEnd PC and a Linear Power Supply :

So, my XXHighEnd PC goes through the "power meter" and I learnt to observe it very frequently, just to see and learn how what I see is or can be related to SQ. Fine;

Yesterday we had to prepare a 115V NOS1 and we connect that through a 230 -> 115V transformer. This transformer is connected to a normal house ring to which ring I may connect switching supply bricks and more sh*t spitting devices related to the audio stuff (could be USB3 disk etc.).
Normally all the normal audio gear is connected to the separete(ly earthed) audio ring and this comprises of PC, NOS1 and amps. Only the PC is connected to earth (PE).

So the change with this 115V NOS1 is that it is actually connected to the normal house ring (through that transformer) while normally it is on the audio ring.

PC is connected as always, like 230V-AudioRing -> Power Meter -> PC.

And in this situation the power meter goes bananas;
It more often shows something like 0.5W and 2W or even 0W than the normal reading which would be around 50W.

I have no idea what this means and to what degree the "power" may be supplied through illegal (groundloop) means or whether possibly the meter is suddenly unreliable because of ... ??

It looks a bit similar to my previous report about the meter being able to show a way low usage (which I think was with Windows 8.1) but this was hard to catch. Now, it almost continuously shows this low usage and clearly (?) it must be related to that tranformer in the chain or using that other ring together with the audio ring.

That no two rings with separate PE should be used was already clear to me (protential difference implied between the two earths) but this seems to show more "nasty" behavior, up to "illegal".

As I said, just to share.
Peter



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on December 02, 2013, 12:01:41 am
Hi All,

I just thought that I would add an update to let you know where things are up to with the Linear ATX Power Supply.

Several options for assistance with the development of this project have been considered and weighed, from using an amalgamation of off-the-shelf power supplies to lots of help from afar from Peter and many things in between.  As Peter has realised from our email correspondence, not only do I like to do things right but I like to get them right the first time and I also tend to err on the side of overkill as well.  I will happily spend extra time to make sure that I get things right first time rather than rush the project.  So with that in mind I have enlisted the help of a friend that is an Electrical Engineer with a rabid passion for audio, especially the diy variety, who has his head screwed on and is not prone to fads and audio mysticism.  In effect I am the ideas man and my 'partner' in this is the brains that will get it working properly.

We have corresponded a lot so far on this project, often several times a day with ideas and ways to get past certain limitations but have come up a basic plan.  Design has started on the PCB's for this project and good progress is being made.  All in all this equates to an awful lot of time and effort but hopefully at the end of it there is a power supply that improves PC audio.

The basic idea as it stands right now, it to have a primary PCB for the 24 Pin ATX socket of the motherboard.  This will have three rails (12V/5V/3.3V) and will also include all of the logic for proper computer startup and shutdown.  This PCB will also be able to control up to five satellite power supplies that may be used in other parts of the computer i.e. P8 CPU and SSD/HDD and USB3 card and optical drive et cetera.  In the end, the computer will turn on and off the exact same way that it does now, but there will be a very high quality, reasonably modular, and reasonably intelligent linear power supply. 

We are going with largely SMD components in an effort to keep the size down but at this stage it is unknown whether we can get this to all fit inside the XXHE PC.  It looks pretty close to me.  Fingers crossed.   


Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: juanpmar on December 02, 2013, 02:16:51 am
Hi Anthony,

I read some time ago from you that this is going to be a DIY project, is it correct?.

I hope you have success in the end and we can all benefit from this power supply. Anyway from here I congratulate you for your effort and I encourage you to go ahead  :thankyou:

Thanks,
Juan


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on December 02, 2013, 03:14:19 am
Hi Anthony,

I read some time ago from you that this is going to be a DIY project, is it correct?.

I hope you have success in the end and we can all benefit from this power supply. Anyway from here I congratulate you for your effort and I encourage you to go ahead  :thankyou:

Thanks,
Juan

Thanks Juan,

It is a DIY thing at this stage until we have a design that is tested and measured and final.  After that there will need to be some sort of production so that the people that want one can get one, but I have not thought too hard about how that is going to work, just that it will happen if the product is a good one.  I certainly don't want to build them myself, so we will have to find someone to do it, but that is a bridge that we will cross when we get to it.

Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on December 02, 2013, 09:02:56 am
Hi there Anthony,

So, still going strong eh ? Good.

Well, if it isn't going to fit in this case, we'll have to find another. The only downside will be that it will be larger. Haha. But for now we shouldn't worry about it.

Don't hesitate to let us do the soldering. In that case, also don't hesitate to make it SMD 0403 if that can gain a lot for the PCB size. But only then, because 0403 isn't even visible. Haha.

I don't know whether your EE can solder this himself (or in his company ;)) but if this is a problem, you may consider to send me the Gerber files (these are files which contain all about the PCB layout so they can be produced automatically) so I can have them produced, sent to me, source the parts and solder them. Next step I am not sure about, but logically I would send the lot to you out there. I would do that all for free.

Keep in mind that this is mainly about the soldering which has to be done manually (otherwise it will be unaffordable) and that this thus is about needing someone who can do that.
Also don't forget that having made a few proto PCBs does not need to cost much, but as soon as you/we need 20 and more you will loose heavily on it, and hopping over to normal production will cost, say, 150 euros for the design (in the production company). IOW, never apply prototyping when you head for "production" and thus start out with "production" right away. This means paying 150 euros for the design plus maybe 2 euros for the PCB (or 1 euro for the larger quantities) and for a repeat order de PCB remains that 2-1 euro.
Prototyping may cost 5-15 euro per PCB (depending on the size - usually goes per square dm) and no design costs. And quality is worse.

Your EE will know the abouts too but he really needs to be all over in the project in order to make the right decisions which in the end IS all about money - money the consumer needs to pay.

2c :)
Peter


Title: XXHighEnd PC Stripped down
Post by: PeterSt on December 02, 2013, 09:30:02 am
Here's a few thoughts on what can go out of the PC when space is needed :

Notice : This anticipate today's views on how the PC operates best, which is with the least devices connected.

The internally assembled 2.5" disk. You won't gain much here, except when the whole bracket can go to which it is fitted.

Obviously the normal ATX PSU. This is more or less related to mentioned bracket. I am doing this by heart, thus not looking at the PC right now ... Thus, remove the PSU, remove the bracket which is over it and nothing is left at that right side.
But also no 2.5" removable bay and no DVD drive. :swoon:

On the left side there are the two removale 3.5" bays. The bottom one can be removed and the top one can be removed as well but this latter can be replaced with a 2x 2.5" removable bay including DVD. Think the size of that device now being on the right side. Not sure how to fit it because it will need a kind of bracket as is on the right side.
Accidentally I will receive such a "drive" one of these days so I can have a look whether that can be mounted in the left side somehow.

I can't oversee (without looking at the PC) whether anything can really be gained on the left side because I think it will be over the MoBo there. On the other hand it won't be all that difficult to have a bracket/plate made that fits over the MoBo there and where maybe a pile of capacitors can find their place.


Having said this all, this came to my mind :

Just have a second same box. Cost for that an additional ~100 euros (plus additional shipping roughly estimated on 100 euros for "average" parts of the word because of the total size of all !). Now use a nice umbilical cord for the power connection from the one to the other. That would fit all.
Now two of these cases can nicely be stacked and I don't think that will make anything worse (one larger case will I think).

Just give this some thoughts ...
Peter



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on December 02, 2013, 10:54:08 am
Hi there Anthony,

So, still going strong eh ? Good.

Well, if it isn't going to fit in this case, we'll have to find another. The only downside will be that it will be larger. Haha. But for now we shouldn't worry about it.

Don't hesitate to let us do the soldering. In that case, also don't hesitate to make it SMD 0403 if that can gain a lot for the PCB size. But only then, because 0403 isn't even visible. Haha.

I don't know whether your EE can solder this himself (or in his company ;)) but if this is a problem, you may consider to send me the Gerber files (these are files which contain all about the PCB layout so they can be produced automatically) so I can have them produced, sent to me, source the parts and solder them. Next step I am not sure about, but logically I would send the lot to you out there. I would do that all for free.

Keep in mind that this is mainly about the soldering which has to be done manually (otherwise it will be unaffordable) and that this thus is about needing someone who can do that.
Also don't forget that having made a few proto PCBs does not need to cost much, but as soon as you/we need 20 and more you will loose heavily on it, and hopping over to normal production will cost, say, 150 euros for the design (in the production company). IOW, never apply prototyping when you head for "production" and thus start out with "production" right away. This means paying 150 euros for the design plus maybe 2 euros for the PCB (or 1 euro for the larger quantities) and for a repeat order de PCB remains that 2-1 euro.
Prototyping may cost 5-15 euro per PCB (depending on the size - usually goes per square dm) and no design costs. And quality is worse.

Your EE will know the abouts too but he really needs to be all over in the project in order to make the right decisions which in the end IS all about money - money the consumer needs to pay.

2c :)
Peter


Yep still going strong.  I was not sure whether you would want to do the production side of things Peter, but I am very happy if you do.  My EE friend does SMD solder but like me has no interest in doing production volumes so I think we can figure something out.

We are trying to limit the 3 rail ATX PCB to 160mm x 100mm (which is an Eagle software limit) including the rectifier bridges and ATX control logic.  There is also a satellite dual reg board for the super low noise 5V 1A supplies (SSD and USB card) that will be around 100mm x 80mm (for everything but the transformers) but it will not require heatsinking so will have some flexibility for placement.  We have not yet looked too hard at the supply for the P8 cpu but I think it will need quite a bit of capacitance (hence size) and it will need considerable heatsinking so it will probably stay within the main LPSU box with the ATX PCB.

I am dubious about long umbilical cords between an external psu and the computer, mainly because of the possibility to induct noise on our clean power.  If I had my way I would get a pc case so that I could direct connect the linear psu into the P24 socket of the mobo - no wires at all and then have the more critical ultra low-noise supplies close to the ssd and USB card (but controlled by the ATX LPSU) for the same reasons.  Anyway, that is probably being pedantic.   

Cheers,

Anthony


Title: Re: XXHighEnd PC Stripped down
Post by: acg on December 02, 2013, 10:59:54 am
Here's a few thoughts on what can go out of the PC when space is needed :

Notice : This anticipate today's views on how the PC operates best, which is with the least devices connected.

The internally assembled 2.5" disk. You won't gain much here, except when the whole bracket can go to which it is fitted.

Obviously the normal ATX PSU. This is more or less related to mentioned bracket. I am doing this by heart, thus not looking at the PC right now ... Thus, remove the PSU, remove the bracket which is over it and nothing is left at that right side.
But also no 2.5" removable bay and no DVD drive. :swoon:

On the left side there are the two removale 3.5" bays. The bottom one can be removed and the top one can be removed as well but this latter can be replaced with a 2x 2.5" removable bay including DVD. Think the size of that device now being on the right side. Not sure how to fit it because it will need a kind of bracket as is on the right side.
Accidentally I will receive such a "drive" one of these days so I can have a look whether that can be mounted in the left side somehow.

I can't oversee (without looking at the PC) whether anything can really be gained on the left side because I think it will be over the MoBo there. On the other hand it won't be all that difficult to have a bracket/plate made that fits over the MoBo there and where maybe a pile of capacitors can find their place.


Having said this all, this came to my mind :

Just have a second same box. Cost for that an additional ~100 euros (plus additional shipping roughly estimated on 100 euros for "average" parts of the word because of the total size of all !). Now use a nice umbilical cord for the power connection from the one to the other. That would fit all.
Now two of these cases can nicely be stacked and I don't think that will make anything worse (one larger case will I think).

Just give this some thoughts ...
Peter



I've got Robs XXHE PC here at the moment (you know Rob - new NOS1 owner here in Oz) and he has put it in a larger Streacom case which has loads more room than the standard case.  There is always an option like that.

 


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: pedal on December 02, 2013, 11:03:22 am
Yes, PSU in a separate cabinet is highly desirable, both for heat issue and (probably) sound betters, too.

I am keen to buy this combo when the linear PSU issue is solved.

A screened cord with an added ferrite snapped on at the PC-end avoids any pick-up of radiated noise. This I know as a fact, from a very serious manufacturer of high end DAC and amplifiers.
Contrary, putting the PSU inside a cramped cabinet might create more radiation problems, due to the magnetic fields of the coils.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on December 02, 2013, 11:09:04 am
Quote
Anyway, that is probably being pedantic.

No, maybe not. But I figured that the regulator board (if there, but you just said so) can be in the actual PC case, the transformers and capacitor banks in that "PSU case".

Of course it all depends on how you guys see the general design and how critical the current space is to begin with.

What was also in my mind is the heat;
So, while you talk about "conciderable heatsinking" I think you can forget it do have that inside of the normal PC; you will never get out the heat unless 70dB fans are in there (per piece, so that totals to 210dB hahahaha - I actually wonder why calculators never contain dB math);
With the external box that probably still won't go (but notice that that too is "fanned"), but *there* you have the opportunity to make a nice heatsink at the back side (say where the PCI brackets normally are). Where the PSU normally sits is another space for that.

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on December 02, 2013, 11:33:05 am
Yes, the transformers in a separate case makes good sense.  At this stage the heatsink will be on the back of the PCB and I had considered the PCB to be placed vertical with a fan or two to move the air where it needs to go which is out of the top of the case.  Anyway, we really wont know until the design of the ATX PCB is finalised and we know its size and final heat ratings.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on December 09, 2013, 06:12:53 pm
Anthony,

Although at this moment it is great fun for only myself, look at this post : Re: USB Clock Upgrade My Experiences (so far) (http://www.phasure.com/index.php?topic=2784.msg29198#msg29198) ...

My personal fun - but it could be important later for your topic here, is that my secret connection looses 5 Watts of usage in the PC ... at least. What I'm doing now is in  Normal OS Mode, a couple of screens open, and I'm at 45 Watts. Ha !

:bye:
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on December 09, 2013, 09:18:33 pm
That is a big drop Peter...10% or so at this stage of the game is substantial.  Are you using 5v to power your 'special connection'?

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on December 10, 2013, 07:10:28 am
12V Anthony. But this is not relevant. :secret:


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on December 10, 2013, 07:21:19 am
Ohhh shoot ! At writing this last little post I just thought of another trick. Oh boy, this is going in a very strange direction now ...

I said OMG in that other topic, I will now say that for this one again.

Uh-oh ... If it only can work ...
But relatively easy to find out. Today for sure.
Man, I am MEAN.
:smirk:


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on December 10, 2013, 08:00:00 am
hehehehe. We have a saying over here that we bring out whenever someone is in good form:  "you go you good thing"  :clapping:


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on December 10, 2013, 02:38:14 pm
Well, so far already the simplest thing fails and I don't know why. Must try more later.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: Arjan on December 21, 2013, 06:39:12 pm
Hi,
I am still thinking of a test with a picoPsu and linear psu on my pc.
Searching the web I saw this product: 4M-ATX-HV. This is used to power computers on cars and boats. Might be interesting.
Regards


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on December 21, 2013, 07:32:05 pm
Ahum

Arjan, that 4M-ATX-HV item number sounds familiar to me, but I am not even responding to that at all. But about cars and boats, yes ...

Djeeeeeeeeeeeeeeeezzzzzzzzzzzzzzzzzzzzzzz

Freakin' stupid me only now recalls that he has 20 completely ready LPSU's for PC's in stock somewhere. Man, what a fool I am. Shiiiiiiiiiiit. Bought from a suspended railroad line something like 12 years ago. Think Orient Express but then from Holland (??) to Austria I think. Such an expensive line with all in there to enjoy yourself.

Envision :
Some trader offers 20 touch screen PC's (fairly rare at the time), completely custom built for that railroad and those PC's serving as point of sale terminals in the restaurant. PentiumIII I recall. Most of the screens were broken. PC cabinet (nice 30 degree or so upward touch screen) plus a 10-15Kg supply. I think there is something like a car battery in there.
So, we with a bunch of trolly's by elevator down to the car parking place (a garage) and it was totally crowded and I was waiting for ages until my wife came back with the car from the garage. The whole pavement filled with all this stuff and not in the most nice neighboorhoud (waiting to get robbed of the lot) - no idea yet how to ever get it in the car (but we managed).

The least I can do is finding out how this is all organized in these (two) cabinets and try to get it running for a normal PC ...

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on December 22, 2013, 03:38:55 am
Hi,
I am still thinking of a test with a picoPsu and linear psu on my pc.
Searching the web I saw this product: 4M-ATX-HV. This is used to power computers on cars and boats. Might be interesting.
Regards

Hi Akremer,

I would use the pico rather than the 4M thingamy (I assume you transcribed the 4 & M the wrong way around??)...you don't need the cranking protection or some of the other things on that board.  The pico is designed for standard installations and the 4M is designed for vehicle installations, so unless your computer is in a vehicle the pico is easily the best choice in my eyes.  You will still need a heftly LPS to supply the pico.

Cheers,

Anthony

EDIT:  Apparently you can run the wide input pico from a battery as well if you wanted to go that way.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on December 22, 2013, 03:48:28 am
Ahum

Arjan, that 4M-ATX-HV item number sounds familiar to me, but I am not even responding to that at all. But about cars and boats, yes ...

Djeeeeeeeeeeeeeeeezzzzzzzzzzzzzzzzzzzzzzz

Freakin' stupid me only now recalls that he has 20 completely ready LPSU's for PC's in stock somewhere. Man, what a fool I am. Shiiiiiiiiiiit. Bought from a suspended railroad line something like 12 years ago. Think Orient Express but then from Holland (??) to Austria I think. Such an expensive line with all in there to enjoy yourself.

Envision :
Some trader offers 20 touch screen PC's (fairly rare at the time), completely custom built for that railroad and those PC's serving as point of sale terminals in the restaurant. PentiumIII I recall. Most of the screens were broken. PC cabinet (nice 30 degree or so upward touch screen) plus a 10-15Kg supply. I think there is something like a car battery in there.
So, we with a bunch of trolly's by elevator down to the car parking place (a garage) and it was totally crowded and I was waiting for ages until my wife came back with the car from the garage. The whole pavement filled with all this stuff and not in the most nice neighboorhoud (waiting to get robbed of the lot) - no idea yet how to ever get it in the car (but we managed).

The least I can do is finding out how this is all organized in these (two) cabinets and try to get it running for a normal PC ...

Peter

Peter, these are interesting and most certainly worth opening up to have a look.  I would think that if battery powered they would use a simple dc-dc converter (like a modern-day pico psu) to power the computer.  I would rate it highly unlikely that they would use linear regulators at all because of efficiency issues in that environment of a rail carriage.  You never know though.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on December 22, 2013, 03:50:00 am
Plus the ATX Power spec has moved on a long way from when PIII computers were commonplace, they may not even startup an X79 motherboard.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: Arjan on January 19, 2014, 03:19:01 pm
Hi,
I have my computer running on a picoPsu with a linear supply. And the sound is fantastic!
I use 2 small linear supplies for the external harddrive and fans in the computer. (5v and 12v).
And 1 large supply for motherboard, processor, Graphical card and usb card. (12v) This supply is a qj3020s.
Regards,


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on January 19, 2014, 04:07:11 pm
Hey hey !

I didn't investigate it, but do you think more people have it working with a setup like yours Arjan ? I mean, it almost looks too easy suddenly ...

Regards,
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: Arjan on January 19, 2014, 06:48:52 pm
Hi Peter,
I do not know. It sounds easy, but I changes the cooling fans to less noisy ones and made them adjustable.
Also the power supply is heavy and in a closed cabinet gives some issues with heat. And two times the computer restarted without a reason. So stability seems less than with a normal atx supply. Is it the picoPsu?
I think this is not a final solution. But now I know what a good linear supply can do.
The power supply does never go above 6A (12V) so that seems to be far below the limits of the picoPsu. (160 xt with 200watt peak)
I will use this setup the coming weeks and see how it proceed.
Regards


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on January 19, 2014, 10:51:52 pm
Glad you have it working Akremer!!  I am also glad that you notice a sound improvement.  Could you please describe the changes?  The picoPSU won't be causing the restarts unless it is faulty...I have used them before to good effect with no problems.

Peter, this is a reasonably common setup:  a relatively large, low cost LPS feeding a picoPSU into the motherboard and then smaller LPS's for the peripherals such as the SSD/HDD etc..  Depending on the version of the picoPSU, the 12V may be passed through to the mobo unscathed but the other rails are all derived via switching regulators, which sort of defeats the purpose to a certain extent, but it still is should be a step forward.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: Arjan on January 20, 2014, 09:18:41 am
Hi Anthony,
About the SQ: overall more rest. We were able to play the music louder then before.
The soundstage is deeper! And more details can be heard.
The notes seems to be longer, and the voices are really nice. The SQ is really a step forward.

Before I used the same bequiet atx psu as used in the xxhighend pc.

I also switched (later on) from the Paul Pang usb to the Silverstone (isolated) usb. I do not have issues with Ssss's. They are there but really depending on the recordings and voice. Maybe later I will make the changes to the Paul Pang and try that card again. but for now I like the Silverstone.

I am also thinking about buying the Paul Pang picopsu, to see the improvement on a standard picopsu.

regards,
Arjan


Title: Re: XXHighEnd Eliminated ?
Post by: manisandher on May 12, 2014, 08:15:24 am
I think it's probably worth noting that what Peter seems to have done is eliminate the influence of the USB interface. The NOS1 will still be heavily influenced by both platform and airborne vibrations. Maybe electrical noise via the AC mains will still play a part? If so, isolating the PC's SMPS from the NOS1's AC power supply may still be beneficial.

Mani.


Title: Re: XXHighEnd Eliminated ?
Post by: acg on May 12, 2014, 08:49:07 am
I think it's probably worth noting that what Peter seems to have done is eliminate the influence of the USB interface. The NOS1 will still be heavily influenced by both platform and airborne vibrations. Maybe electrical noise via the AC mains will still play a part? If so, isolating the PC's SMPS from the NOS1's AC power supply may still be beneficial.

Mani.

I have had this thought about the LPS also Mani.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on May 16, 2014, 12:01:49 pm
Mani,

Quote
Maybe electrical noise via the AC mains will still play a part? If so, isolating the PC's SMPS from the NOS1's AC power supply may still be beneficial.

It well can be but at this moment I don't know how to prove that.

(http://www.stordiau.nl/Phasure NOS1/Supply Noise (white) vs output noise Pos. rail FFT.png)

If you look at the excursion just before 18KHz - that's my dreaded PWM heating pump (not heat pump, which is something else). To the left of that the first next peak at almost the same level is the freezer. Both are on a totally separate mains ring (incl. different earth pin). Nothing, really nothing can take that out because it comes through air and sneaks into all, including the other mains ring(s) with different earth pins. You see it here at -140dB because it was "tweaked" that and this is all about the DAC's grounding (say guiding away).

If we look at e.g. 65Khz then I don't even know what that is. Same for the other spuria on the right hand side. It could be PCs, it could be anything. And then to think this sees 96Khz only, while beyond that there's quite some more, and especialy the very high frequencies may show nasty things. But next problem : how to measure *that* because no high bandwidth analyzer will show noise that deep. Merely think 120dB down max and if you envision that to have happened in the picture above, well, all would be completely spuria free !
Ehm ...

Next is that we don't even know how for example the still present stuff at -125dB as the worst (the 65KHz) will be able to influence for example the oscillators. Or how it may be able to the D/A conversion itself with its utmost small currents (as explained elsewhere).

As you can see I try to approach it from the measurement level and not from the audible level; I regard this latter too difficult anyway; it must measure good first, and now there's thus a small conflict.
Also, all already starts with good measurement. Like here you see the lower frequency sh*t which is from plain lousy measurement or the maybe inability to lead away the probe lead sufficiently from the power supply.; all it tells is that it won't be worse, but it doesn't tell a thing about how much better it can be. Of course, when behind the wheel this is fairly easy to check (move the probe lead and see if something changes) but now notice that each measurement has a purpose and really requires preparation and approach. Nice example of this is the 1GHz analog measurement which superbly shows how I can't even press the print screen button on that scope because I create a field myself and the beam moves already by that (you can see that by the misalignment of the Delta-T cursors compared to the beam it should embrace (and which it did).

This was all a fairly long talk about "all is moot anyway" because too much out of out control.
And of course, when we exchange our freezer motors with one that doesn't spit like all undoubtedly do we are under control more. We could end up in a bunker in the middle of nowhere without fridges and all, but we would have warm beers in there and no dishwasher to clean the glasses. This latter is OK because no beer glass is to be cleaned in a dishwasher, but still.
But only then we can be sort of guaranteed that stopping a PC from spitting will help, just because it will be the last bit of it.
But will it influence anywhere ? Maybe we go too far ?

You don't know it much, but in the not-isolated situation we would see a fairly high spike at 8KHz of USB noise. I forgot by now, but towards -100dB in above picture. From something like that we can at least reason out that it will influence the oscillators to begin with. My pump I could not see, which only happens now because the noise is more down. So now that will influence ? Well, don't think that without checking, because behind what you see here is another ultra low noise supply which is thus fed first by what you see (white trace) and of which I can expect that nothing any more shows but I will only know when I measure *that*. This will count for any PC spitting too, and everything else.

But yes, that is what I can do more at this moment; measure the supply noise to the oscillator(s); I'm fairly confident that nothing will change to my pump's visibility (because that is always a matter of guiding out and I don't know how to do that better) but possibly we can learn something from the remainder. And then still not easy, because who says if I put up the same measurement now, it shows the same; can be a matter of the neighbors just finished with the dishwasher.

Peter



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on May 19, 2014, 09:39:47 am
Quote
But yes, that is what I can do more at this moment; measure the supply noise to the oscillator(s); I'm fairly confident that nothing will change to my pump's visibility (because that is always a matter of guiding out and I don't know how to do that better) but possibly we can learn something from the remainder.

So, did that. But funny ... nothing changed much apart from just that pump.

(http://www.stordiau.nl/Phasure NOS1/Supply Noise (white) vs output noise Pos. rail Osc 04 FFT.png)
This is all what's left of the pump (17700 HZ) and in the left the freezer.

Here the clock supply noise (this is 3.3V positive) :

(http://www.stordiau.nl/Phasure NOS1/Supply Noise (white) vs output noise Pos. rail Osc 01.png)

And might someone recognize something in these details (possibly regarding SPSU's) :

(http://www.stordiau.nl/Phasure NOS1/Supply Noise (white) vs output noise Pos. rail Osc 07 FFT.png)

(http://www.stordiau.nl/Phasure NOS1/Supply Noise (white) vs output noise Pos. rail Osc 08 FFT.png)
So that is all I have for unrecognized anomalies.

Peter




Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on May 19, 2014, 09:47:36 am
Peter,

Can you please confirm just what you did to remove the pump noise from your noise plot?

Cheers,

Anthony



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on May 19, 2014, 09:52:36 am

And might someone recognize something in these details (possibly regarding SPSU's) :

(http://www.stordiau.nl/Phasure NOS1/Supply Noise (white) vs output noise Pos. rail Osc 07 FFT.png)


Roughly 50Hz harmonics?  You guys in Europe have 50Hz mains don't you?  SMPS for various appliances.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on May 19, 2014, 10:10:02 am
Quote
Roughly 50Hz harmonics?

Anthony, hmm ... I did not even see that. But is there any logic in why only there ? So all is quiet, expect for that little area.

And of course in the lower region. Here :

(http://www.stordiau.nl/Phasure NOS1/Supply Noise (white) vs output noise Pos. rail Osc 03 FFT.png)
Beyond that it stops. Except for that small area ...

:scratching:
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on May 19, 2014, 10:35:41 am
Can you please confirm just what you did to remove the pump noise from your noise plot?

Funny man ...

Nothing. Or nothing that I know of. But remember, this is a supply fed with the other supply from the screen shot of a couple of days back (few posts up now).

What I expected is that the 50Hz would be better rejected (say another time "filtered"), but that did not happen. So I guess this is too much transformer (AC) influence or pickup indeed. This time I took care (to some extend) that no probes were routed over "doubtful" places, but I don't think I saw a difference.

Notice that there is more to it than just "applying" a very low noise supply and that it is all related to how much headroom you give the regulator (that's what it is) to flatten the "ripple" (can we call it that ?). So envision (and correct me wherever I look suspicious) a voltage wave which is e.g. 7Volts but now in RMS terms. So this wave is no nice sine at all, which is what we are doing this in the first place. Now, the extensions of the wave are sort of shaped off until the wave becomes a nice sine. So, it is not so that the deep dips are are filled up with new "voltage". It is only shaping. So, if the dips are too deep then dips remain. I think I can even see that on the noise base for what it's *under side" is concerned (see the "ripple").

Now, when the input voltage is 7 and the output is 5, then maybe the dropout is too low (too few). Thus, make that 8V and the dips rise as well, and when (virtually) the dips stay above the 5V level, the 8V can now be shaped to 5V neatly.

The whole thing is fairly complex because all is related. So before you know the transformer is too small (to enable the e.g. 8V DC) and the larger one implies too much heat on the AC/DC towards/in the main PSU. So there actually the same happens ("shaping") and what's thrown out is heat. Similarly, now having a nice 8V to shape into 5V also takes additional heat. And as you already know Anthony, this heat can be of big concern because before you know it no PCB with sufficient cooling copper will fit anywhere, nor will heat sinks. So all is a matter of feasible balance and the main issue is always heat.
And heat again implies (thermal) noise so that already makes it worse again.

So this is my reasoning about the 50Hz (or 60Hz, won't matter) with of course my remark that this is all fairly new and no idiot should be looking for such low noise in the first place. As I told earlier - when the noise would be all over at -120dB to begin with, you wouldn't see 50Hz either.
Of course I still wonder (or am challenged/intrigued) what would happen when the whole AC to DC business would be at several meters distance. Just to be 100% sure it is not pickup.

Thanks,
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on May 19, 2014, 11:20:58 am

So this is my reasoning about the 50Hz (or 60Hz, won't matter) with of course my remark that this is all fairly new and no idiot should be looking for such low noise in the first place. As I told earlier - when the noise would be all over at -120dB to begin with, you wouldn't see 50Hz either.
Of course I still wonder (or am challenged/intrigued) what would happen when the whole AC to DC business would be at several meters distance. Just to be 100% sure it is not pickup.


Yes, this was one of the things that I thought could be important in the ATX LPS project.  The design had matured to a stage where all the AC to DC stuff was to be done in an external box along with pre-regulation (in DC of course) and then inside the computer the final regulation was to occur so that the antennae effect of the longer DC wires could be reduced and so that the final regulation occurred right at the load.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: Arjan on May 23, 2014, 09:06:54 pm
Hi,
While waiting for a NOS1a in the very near future I did a final linear psu upgrade on my XXHE pc. And I am surprised about the stepup in SQ.

As you see in my profile I am not using a NOS1 but a AP2 + purepower usb - spdif converter to a NAD m51.
For my pc I use a Paul pang picoPsu feeded from a linear lab psu. But I removed the silverwire of the picoPsu, because I do not like silverwire, and replaced it with better 'copper' wire. The external esata hdd together with the pc fans are powered by 2 separate linear lab psu's.
Next there is the usb card, it is a Silverstone card but with a twist, I replaced the clock with a Paul pang clock. I feed the usb card with 2 linear psu's. The 3.3v from a linear lab psu. But, and that works remarkably good, for the 5v I use a aqvox linear psu. It was used for clean usb power but I put a molex connector on it to connect to the modified usb card.
This last upgrade, the aqvox on the usb card, made a significant difference. I think the ripple of the psu is <0.1mV.

This has raised the bar for the next to come NOS1a. But it needs 5 linear psu's for the XXHE pc to get this far!
I expect that with the NOS1a I can detach all the wires and psu's from the pc and go back to a normal decent atx psu. We will see......

Regards, Arjan


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on May 24, 2014, 06:29:57 am
Great stuff Arjan !

It is strange ... I think I am not the only one who hopes that these kind of tweaks still keep on working for the better ...

:cry:
Yes, sometimes I think "what have I done".
But then if you hear it ...  :)

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on January 22, 2015, 09:23:51 pm
Hi Peter,

Given your recent efforts with super low noise clocks in the NOS1a and Nick going nuts with clocks here there and everywhere in the PC, perhaps it is time for me to resurrect this project.  Maybe this will help with the next rounds of advancement in computer audio.

Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: Scroobius on January 22, 2015, 10:06:33 pm
Mani has a linear PS on order for his PC..........



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on January 22, 2015, 10:17:03 pm
Mani has a linear PS on order for his PC..........



Which one?  The couple that I have seen are not that great.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on January 22, 2015, 10:25:24 pm
Or don't work for everything and all, that I have seen. My "own" is among those. Project is officially still running, but not much news I'm afraid.

In other words, Anthony, no need to bet on one horse, especially when all run slow. You could catch up.
But you can only tell afterwards.

Regards,
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: Scroobius on January 22, 2015, 10:48:12 pm
Quote
Which one?  The couple that I have seen are not that great.

Mani did mention but I had my head buried in his PC at the time so do not recall - Mani?


Title: Rebooting the ATX LPS Project
Post by: acg on August 18, 2015, 08:56:18 am
Well, with nothing happening on this front since I learned about the computer immunity of the NOS1a.  However, considering a few anecdotes of improvements from a computer LPS and Peters half-enthusiasm due to his workload with the NOS2 I have decided to revisit this project.  But the scope has changed a little with the technical advancements of both the Phasure system and linear regulators in general.  Ultimately, I want to find out just what it is about a linear power supply for the computer that can influence sound with our dacs, so I plan to go about things from two angles:

  • An ATX LPS similar to those already on the market using the same voltage regulators, but in what is probably a better, lower noise way.
  • An ATX LPS with new technology that surpasses existing supplies in terms of low noise, ripple, psrr, impedance et cetera.

Obviously this means that I will have to make at least two power supplies with different technology and see if they cause the system to sound different.  With the new technology I should be able to keep noise around 100 times lower than the tech. used in the commercially available power supplies.  Will this make a difference?  Is it the noise/ripple/psrr that makes a difference or is it simply about lowering the amount of noise fed back into the mains supply?  Is there a difference at all and is it work going all-out with the power supplies?

Anyway, I have been busy lately and am working on the module that will interface with the motherboard and control the power supplies.  I am quite confident that I can get it to work and once I do I can then play with the "good" power supplies (say 1mV RMS noise @8A and 4.5uV RMS noise @ 1A) and the "great" ones (say 15uV RMS noise @8A and 0.4uV RMS noise @ 1A).


Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on August 18, 2015, 09:38:48 am
Very interested to learn about the results, Anthony.

If I can do something, of course you'll let me know ...

Best regards,
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: AlainGr on August 18, 2015, 01:14:33 pm
This is still something I would like to apply to my audio PC, since I believe that correcting problems right at the source may eliminate the need to apply "band aids" further down the chain...

Regards,

Alain


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: toddn on August 18, 2015, 04:58:08 pm
Hi Anthony,

I have 3 separate Acopian high grade power supply's with .25mv ripple and .005% line regulation, one for each MB voltage rail. (See attached spec. sheet.) I've been meaning to use your wiring & power up sequence research cheat sheet to give them a try, just haven't gotten around to it.

I'll try to get to it this weekend and report my results here. Maybe it will provide some additional useful information. I hope so anyway.

Todd


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on August 18, 2015, 05:09:32 pm
Todd, I have resized your image a bit, so it is better readable.

Thanks,
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on August 18, 2015, 05:21:32 pm
Todd, I only say this so that Anthony doesn't need to possibly embarrass someone :

Anthony talks about 14uV at 8 Amperes, while you talk about 250uV at 8 Amperes.
Also from your picture I can derive that at 8 Amperes it will merely be 1000uV.

Quote
then play with the "good" power supplies (say 1mV RMS noise @8A

1mV = 1000uV

Now that is out, please continue. :) :)

Great stuff ...
Peter


PS: And nobody claims that there will be a SQ difference.
Yet.

PPS: Getting something to run seems to be more crucial. At least at first (like in : mine didn't want to boot, no matter Anthony's sequence which I also tried).


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: toddn on August 18, 2015, 05:36:00 pm
Ah yes, I see now. micro volts vs. millivolts

Thank you Peter.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on August 18, 2015, 05:48:41 pm
Seems quite unbelievable anyway, Todd.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on August 18, 2015, 05:51:53 pm
PS:

Quote
Anthony talks about 14uV

No worries. That was a typo. Anthony said 15uV.

8)


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on August 18, 2015, 11:16:03 pm
Hi Anthony,

I have 3 separate Acopian high grade power supply's with .25mv ripple and .005% line regulation, one for each MB voltage rail. (See attached spec. sheet.) I've been meaning to use your wiring & power up sequence research cheat sheet to give them a try, just haven't gotten around to it.

I'll try to get to it this weekend and report my results here. Maybe it will provide some additional useful information. I hope so anyway.

Todd

Hi Todd,

Those Acopian supplies look fine, so I will be quite keen to hear how you go getting your motherboard to start and of course how everything sounds.


Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on August 18, 2015, 11:23:40 pm
PS:

Quote
Anthony talks about 14uV

No worries. That was a typo. Anthony said 15uV.

8)

Yeah 15uV which is quite an astounding noise level really for that amperage.  It is one thing to have a supply that carries that much noise at its outputs, but it is another thing to keep that low noise for the load which may be down a meter or more of cable.  A tricky part will be laying out the supplies inside the computer case so that there are either no leads (as in directly plug in the power supply to the sockets) or the leads are very short, say 10cm or thereabouts.  Of course the lower noise supplies are physically larger because of paralleled regulators and lots of capacitance so they are going to be more difficult to snuggle up next to the things that we want to power.

Ideally I will need a custom computer case to make room for these things...but we will see if it comes to that.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on September 30, 2015, 09:58:43 am
Hey all,

Here's once again a testimony of how complicated things are in Audio ...

So I have a 350W Teradak here at this moment. Beautifully built and it works with the ASRock MoBo.
It is completely silent (no transformer hum). Decent stuff, as it seems.

I decided to first let it work under Windows 8. I am not even sure why, but I guess I want to let work Windows 8 better because it probably *is* better, compared to Windows 10. About that in brief : In my view W8 is way more accurate BUT does not play music. The robots do that. In Windows 10 the musicians play.

OMG

Yeah, what ?

haha

Painstakingly killing. Djeezz, now THAT is bad.
S'es sharp as razors and I don't know what all was missing in the music. Everything, I'd say. Still it was not overly sharp, but it just did not make any sense to me.
I think I gave it 8 minutes, and then W10 was thrown at it.

As expected this made it somewhat better, but actually not at all for net result. Still it made no sense. However, I now could hear a bit better what was going on.
So what was going on ?

No, I couldn't really figure it out. I thought that perhaps a high dose of radiation was in order because actually the PSU was sitting quite close to the DAC and I wondered whether that could hurt.

What happened next gave me a small clue, but only in aftermath. So later more about it. But anyway, what happened is that I tried to move the unit which seemed impossible because of the too short power cord and while I really did not see anything happen in the PSU, moving the cord switched off the PC. Hmm ...

With a longer cord the PSU was moved away for a meter, an extra metal shield was placed and another 20 minutes of annoyance passed.
f*ck

Then I started to be smart and figured that while the normal switching PSU "allowed" to be without mains earth in my setup, that being for the better, nothing would guarantee that this LPSU is supposed to work well without earth connection.
And so another reboot was performed, the PSU now connected to mains earth.

This time a sort of forced rest (of mind) was introduced because after starting a first track I lost all control. Coincidence ? maybe. I had this once before, maybe a year ago. Nothing works, not even the monitor, but music played. So I let the playlist go (appeared to be ~30 minutes) and I noticed that I didn't want to pull the plug.
At the end of the playlist all started working again but by that time dinner was ready as well and I stopped the game.

My moral for this moment :
It is completely impossible to make an apples with apples comparison because I clearly had to change ground paths all over. And do notice that the no-earth for the (same) PC with switching PSU is the best (noise) measuring one; Apparantly this changes with the LPSU although I did not measure anything yesterday.

More tonight, but my hopes are not too high.


Then what I wanted to come back at :
The too short power cord appeared to be one which did not fit too well in the PSU's socket. Say it is a bit loose in there. Probably I created an "invisible" very short disconnect but now I wonder whether the PC was allowed to shut down by that. And notice that I could hear exactly when it happened, because music was playing ...

And so I started to think (later) whether the relative few "capacitor bank" isn't too low for decent operation. Actually I thought about speed and whether with such a low amount of capacitance the speed of a linear PSU is not too low for what's desired here. Uhm, whatever that is. But anyway notice that a switching PSU actually has no cap-buffers at all.
I am not looking at it at this moment of writing, but I think something like 12 or 16 of ~470uF is there for one voltage. That doesn't seem much to me, especially not for the higher current (spikes ?!) in order. And all voltages (the PCB's for it) are assembled the same (for capacitance buffer).

So far for now.
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: AlainGr on September 30, 2015, 12:13:25 pm
Hi Peter,

I am confused by your post... The comparison you make between win 8 is that you find Win 8 more accurate, while Win 10 is more musical ?

And are you saying that the Teradak does not have sufficient reserve power to face sudden demands ?

Thanks.

Alain


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on September 30, 2015, 12:27:39 pm
Hi Alain,

All correct. But :

Quote
And are you saying that the Teradak does not have sufficient reserve power to face sudden demands ?

This shouldn't read as a law or something. I just seek an explanation for a sound which seems to be worse and the logic of an audiophile tells that if capacitors are too small, the sound will be tinny. BUT :
How on earth this makes sense for a computer ... you tell me.

I didn't expect much of a difference anyway but at least with the PSU not connected to mains earth the difference is "abnormal" compared to the switcher in the same situation. Totally failed, I'd say.
Whether things are (really) normalized with the PSU connected to mains earth, I'll have to see about that tonight.

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 01, 2015, 08:13:34 am
So ...

Yesterday has been one of the best nights of playback ever.
It is my conclusion that the LPSU must matter, although I can't really pinpoint it.

I could say that the slight flavour which is in Windows 10 (it is grey-ish) now is not there. It is more snappy - sort of towards Windows 8. Meanwhile the music(ians) kept playing.

Actually it was so that in all of the ~4 hours I never really noticed anything. Nothing jumped out. Nothing disturbed. I didn't want to shut off any album either, meaning that I played a few (in full) only. So my test repertoire wasn't that large this time.

So ...

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 01, 2015, 11:22:11 am
Thanks for the reports Peter.  Have we found a new rabbit hole to go down?  There are several ways to build a good power supply and some guys are doing some interesting stuff over here with choke filtered unregulated supplies such as you would see in a valve amp.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 01, 2015, 09:05:44 pm
Anyway ... here's a visualisation of my rabbit hole.

Still going (very) strong. And no rabbits in there. No rats either.

Btw, the power cord seems to cross the (turqoise) interlink; in reality this is not so (it's at 30cm distance).


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 02, 2015, 09:33:21 am
Would be nice to shorten/eliminate those dc cables or provide a second round of regulation at the motherboard just to see what happens.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: manisandher on October 02, 2015, 10:51:07 am
Anyway ... here's a visualisation of my rabbit hole.

My Teradak ATX 400 (with a 275W output) has a 400W R-core transformer and not a toroidal. Interestingly, my old Pacific Microsonics Model Two PSU also used three large R-core transformers and not toroidals. Is there an advantage in using R-cores over toroidals?

Mani.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: CoenP on October 02, 2015, 11:02:50 am
Sure mani,

R cores have an air gap by their nature. This makes them capable of handling much more DC current than a toroid that has none. Remember the use of DC blockers (anti parallel diodes bridged by a capacitor)? These are applied to toroid PSUs just for this dc reason.

Next to that are r cores easier to wind and have a similar if not better form factor.

Regards, Coen


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: manisandher on October 02, 2015, 11:03:21 am
Is there an advantage in using R-cores over toroidals?

Well, here's a quote from a user called 'uncle-leon' on diyaudio.com:

Quote
Toroids have inherently (relatively) high inter-winding capacitance, and even with a shield between windings I suspect they may be letting in a bit too much mains noise for a digital component.

Any comments anyone?

Mani.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: manisandher on October 02, 2015, 11:04:32 am
R cores have an air gap by their nature. This makes them capable of handling much more DC current than a toroid that has none. Remember the use of DC blockers (anti parallel diodes bridged by a capacitor)? These are applied to toroid PSUs just for this dc reason.

Next to that are r cores easier to wind and have a similar if not better form factor.

Thanks Coen.

Mani.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 02, 2015, 12:32:03 pm
Hey ...

A few comments from my side ...

R-Core transformers are said to be better for audio, but you can find "cons" as well. I forgot myself about the cons, but what remained in my memory is that I should try.

Try what ?
Well, the amplifiers for the NOS2 will also have R-Cores. But I am going to compare with toroids just the same.
Btw, today will be the first day of really listening to them (with toroids). But that is for another topic.

Then :
While I obtained this LPSU from Teradak it is not mine, but for a customer. There is no R-Core in it because I am going to send it out to have it modded (aranged for by the customer). Another transformer is the first mod. I am not going to do anything about it (but listen) because for kind of obvious reasons I don't want to do anything about it in the first place (Anthony, how are you doing ??). It is the customer who arranged all, but it is me to check it with an XXHighEnd PC (and NOS1a).

... But what comes from this is a modded Teradak and I will receive that back to listen again ...

I'm at day 3 now and with 2 more days to go (for my required 5) I don't think it will fail. The most curious thing so far is that all seems to be "normal". So yesterday too, nothing jumped out. No unconscious listening was required - instead do other things and notice in aftermath that you never wanted to change albums.
I even played one of which I knew I liked certain tracks only (the others disturb somewhat). Not so any more.

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 03, 2015, 01:02:27 am
I am not going to do anything about it (but listen) because for kind of obvious reasons I don't want to do anything about it in the first place (Anthony, how are you doing ??).

Hi Peter,

I am edging along but it now sounds like I should pick up the pace.  I built one 5A supply and it tests fine but now I need to get in and build the rest of them as well as the motherboard control circuit for ATX startup and shutdown.  All of the parts are here except a proto board for the control board, which after two months in the post has been forsaken and refunded as of yesterday so I need to chase down another of those to really get the project happening.

How is the W10 expiry going?  I will design the LPSU to best suit the latest hardware so if W10 has not expired I should get you to send out a HDD so I can work with the os running in Ramdisk.

Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 03, 2015, 11:28:22 am
Ok Anthony. No hurries. ;)
A hint could be to start with that boot-up logic.

Regards,
Peter


PS: I am not saying a bootable "from RAM" W10 hdd will be there. I like it to be there, but as long as I can't clone such a disk, it is an undoable task. :offtopic:


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: ed linssen on October 04, 2015, 01:40:00 am

I am edging along but it now sounds like I should pick up the pace.  I built one 5A supply and it tests fine but now I need to get in and build the rest of them as well as the motherboard control circuit for ATX startup and shutdown.  All of the parts are here except a proto board for the control board, which after two months in the post has been forsaken and refunded as of yesterday so I need to chase down another of those to really get the project happening.


Hi, Anthony

Could you  please share what kind of controler you're going to use for the ATX start and shut-down ?
So I can leave my DC/DC converter and the relays I am using now?
Thanks,
Ed



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 05, 2015, 09:49:35 am
So ...

Yesterday was day 6 with the LPSU and it is glory all over.
N.b.: Right now we are packing it for shipment to the person who is going to mod it.

I already feel sad and I want one myself ... (the one I used is for a customer).



Yesterday, knowing that my standard round of 5 days passed in well fashion, I thought to try once again what I felt from the start to be better ... Windows 8.

Ohhhhhhh
was I right.

So far, only in between the lines I have told that Windows 10 isn't the better one at all. However, it performs better because it makes more music. But there's a grey-ish "rounding" flavour.

Big fun : with the LPSU this disappears largely. Maybe even completely. "Maybe" because it is quite hard to pay attention when things sound so good in the first place; as I told - nothing jumps out or disturbs and albums play and play.

Back to a week ago : remember that I started out with the LPSU not in mains earth, and that *that* completely failed. I started with using Windows 8 because I felt or hoped or just knew it should be the better one with the LPSU. But it was misery all over and I shoveled in Windows 10;
Was a bit better but still "non-sense" and then I found the mains earth thing (needs to be used). And then Windows 10 stayed in.

Up to yesterday;
The PSU has to go today, so I sure wanted to try Windows 8 once more.
What did I say ?

Ohhhhhhh

This time I received the "total accuracy" together with music.
Big fun again : I am not even so sure the distance with Windows 10 was large, but Windows 8 just plays "better". Really difficult to explain, but the performers are "better" when played through Windows 8.



So there's a difference of night and day between W8 and W10 when the normal switching PSU is used, and there's hardly a real difference between the two when used with the LPSU.

Now I wonder what this tells ...
Anyone with ideas ?

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 05, 2015, 10:47:38 am

Hi, Anthony

Could you  please share what kind of controler you're going to use for the ATX start and shut-down ?
So I can leave my DC/DC converter and the relays I am using now?
Thanks,
Ed



Hi Ed,

At this stage the controller will be a little SMD board which will do three primary things:

  • monitor voltage and current on three or four power supply rails downstream of the individual rails
  • communicate with motherboard to start and stop the computer
  • control one or more mains relays to control operation of the various power supply rails

Of course I am unfamiliar with your DC-DC converters and relays, but you will be able to connect the output of your supplies to this pcb so they can be monitored and if your relays have 5V coils, are non-latching and NC type there may be enough current available to switch them, but there are no guarantees in that regard.  If you like you can post a link to the datasheet of your relays and I may be able to consider them when I prototype the board shortly.

Regards,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 05, 2015, 10:51:50 am
So ...

Yesterday was day 6 with the LPSU and it is glory all over.
N.b.: Right now we are packing it for shipment to the person who is going to mod it.

I already feel sad and I want one myself ... (the one I used is for a customer).



Yesterday, knowing that my standard round of 5 days passed in well fashion, I thought to try once again what I felt from the start to be better ... Windows 8.

Ohhhhhhh
was I right.

So far, only in between the lines I have told that Windows 10 isn't the better one at all. However, it performs better because it makes more music. But there's a grey-ish "rounding" flavour.

Big fun : with the LPSU this disappears largely. Maybe even completely. "Maybe" because it is quite hard to pay attention when things sound so good in the first place; as I told - nothing jumps out or disturbs and albums play and play.

Back to a week ago : remember that I started out with the LPSU not in mains earth, and that *that* completely failed. I started with using Windows 8 because I felt or hoped or just knew it should be the better one with the LPSU. But it was misery all over and I shoveled in Windows 10;
Was a bit better but still "non-sense" and then I found the mains earth thing (needs to be used). And then Windows 10 stayed in.

Up to yesterday;
The PSU has to go today, so I sure wanted to try Windows 8 once more.
What did I say ?

Ohhhhhhh

This time I received the "total accuracy" together with music.
Big fun again : I am not even so sure the distance with Windows 10 was large, but Windows 8 just plays "better". Really difficult to explain, but the performers are "better" when played through Windows 8.



So there's a difference of night and day between W8 and W10 when the normal switching PSU is used, and there's hardly a real difference between the two when used with the LPSU.

Now I wonder what this tells ...
Anyone with ideas ?

Peter


Thanks for your further comments Peter.  Looks like the ATX LPS is a definite prospect then. 

I have no idea why it brings W8 closer to W10, or vice versa, but it is an interesting thing to speculate.  Are you running both W8 and W10 operating systems from ramdisk without a hard drive of any type in the PC?  I guess I am asking if the hardware is all the same in these comparisons?

Regards,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 05, 2015, 11:22:00 am
Hi Anthony,

W10 runs fully from RAM. No additional RAMDisk (eh, obviously ? <-- I considered that and the space in RAM *is* there (together with the OS), but I just thought it could worsten only). Only device connected is NOS1a and LAN cable.
Video card is in.

W8 Runs from 2.5" HDD. XXHighEnd and Playback Drive on RAMDisk. Only device connected is OS HDD, NOS1a and LAN cable.
Video card is in.

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 05, 2015, 11:55:59 am
It will be way too much of stipulating, but I can think of this :

Earlier on (week ago) I thought of the Linear Supply being "slow". I did not measure that and actually I don't know, but I derive it from common good behaviour of large buffer capacitors we tend to use in power supplies, which "obviously" are always linear.
And in the switching supply the are not there (only a relative small one).

Now let's sort of back fire this :

When the SMPS is very fast and sufficiently fast, where is it "able" to get its juice from ? ... from the mains itself.
This means that it surges the mains in spikey fashion.
Maybe our DAC does not like that so much. Maybe our amplifier doesn't.

With a trained eye I can see how the playback software behaves, although the speed of the power meter is only 2 samples per second. When all is tuned in well fashion (see my sig) then the variation can be 0.5W only.
(side note : d*mn it, I now realize that I forgot to look at the LPSU through the power meter - and now it is packed already. Grrrr !)
The 0.5 W emerges when an SFS round is in order (load a piece of track into memory).

That is the very ROUGH measurement. Super rough, because with 2 samples per second it just *is* super rough.

The meter shows the usage; it does not show any surge (or surging). So I mean : it does not show dropping of voltage or whatever. I just don't know that.

While over the longer term I see a variation in Wattage (0.5), in reality this will be way way waay spikey. So, would I be able to sample 100.000 times per second, then at each sample I would see a difference (in usage). And well, if you ask me, nothing in there is speedy enough to follow (thus surging occurs). Of course no power plant a 100Km away is following my spiky needs, and all what's in there is the "elasticity" of the length of the flow of electrons (which also is 100 Km - or maybe it's from my door step to the stereo only) which could be named "capacitance" I think.

With my back fire I imply an upside down operation to begin with, but I will do that again by stating that no SMPS is spitting noise on to the mains ... no ... it is surging spikes from the mains.

While a week ago I said that the LPSU possibly was too slow (because of not enough capacitance storage), I obviously said that because it sounded bad. But that is history now, and so I put that the other way around : it has so much sufficient capacitance that the mains won't notice much of it, except for the very irregular (randomized) re-charge of all the capacitors (which are 40-60 or so (I still did not count really)).
It's a smooth operation.

The NOS1a is 100% isolated. Still the Q1 etc. stuff makes a difference. Actually crazily easy audible, just because everything went better again (over a year ago I could not hear differences).
So as I often said already : the influence must be creeping in (into the DAC and/or amplifiers) via the backdoor : the mains.

I don't need to say more, because I just already said it all.
But do notice that the influence via the SMPS is almost direct (hardly any buffer) while the influence via the LPSU is very very indirect (buffers all over the place).

Nice.
Now I'm at the beginning of having some clue, I don't have the LPSU any more. I suppose I must get me one. :swoon:

Peter


PS: No, I never touched any SQ dial after things started to work (connect to mains earth). So I also have no idea whether any influence is still there. All I know is that I did not want any influence. Same as that I never turned off *any* album for 5 days (only yesterday I played random tracks because I wanted to hear as many varying stuff as possible). And never turning off any album in 5 days of time ? no, that seriously never happened to me.



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 05, 2015, 12:03:56 pm

One more thing, because you may not have noticed, or I did not rave about it sufficiently enough :

I regard myself to be the loudest shouting person on the Net that a Linear PSU for an audio PC, WORKS. It works so d*mn good that now I don't understand why nobody is shouting about it. And yea, Mani, I know, you "admitted" that it works for you too. But you are the same as the so (really so) many others who obtained the Teradak - initially you are just too quiet. Or anyway quiet enough to not remember any hurays.

Personally I think it is the largest leap by one appliance I ever experienced.

Now I start to be afraid of how tonight's sound will be. I got used to something and ... :scratching:

Regards,
Peter


PS: But it is true ... I too put the results of the LPSU somewhere in between some lines. I am not sure why, but I decided for it explicitly. :yes:


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 05, 2015, 12:50:29 pm
Peter, are you able to experiment with capacitor banks after the SMPS?  Those low voltage caps are pretty cheap.

I really like your thinking regarding capacitance and mains surges, but don't have time tonight to explore it further.  One thing to think about is that there are people that have been playing around with LPS for some time that suggest that a choke filtered supply is the best of the best.  Probably something to do with the shape of the ripple and the choke filtering out the higher frequencies in the noise.

Another thing to think about are snubbers between the transformer and rectifiers.  I have not had a look inside the NOS1a to see if these exist, and I certainly don't know if they are employed in the Teradak, but transformer ringing may be quite an issue for the low noise performance of the NOS1a...I was going to experiment with snubbing down the track but I thought I should mention it now.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 05, 2015, 01:52:36 pm
Anthony,

Actually it is hard to see how filtering the mains (supply) is going to work out. Did you ever look at it (scope) ?
It's monsters in there. Well, over here it is.

Look below; that's not going to be filtered out by anything. It is very regular though.
But careful, this is fooling you because it is 50Hz pick-up through air. It is from this topic : Our great mains (http://www.phasure.com/index.php?topic=1686.msg17016#msg17016). If you scroll down a little, you see this picture coming by.

Notice that *because* of this low level (200mV peak instead of 220V) you can see what is going on. So it is my estimate that on the way larger scale these (regular) excursions are the same, but then relative to 220V (and you won't be able to see them). Anyway, this can be looked at as 50Hz noise (noise with a frequency of 50Hz). Not such a good idea to filter that out ... haha.

I don't know.
Assumed that such a thing (and worse) is reality, this still implies "an RMS voltage" (mind the RMS). It also will imply a very same cycle-to-cycle same RMS voltage because the distortions are completely equal (well, seen at this level). However, when we "surge" somewhat, the voltage will drop ... (and this maybe 100,000 times per second and whatever oscillation (new frequencies) may occur together with the noise you see (below).
Don't ask me, but possibly a mV or even way less of drop on 220V (btw officially 230 and in your country most often 240 I think) *is* audible.

Now you can choke that but we're not even talking about noise as such (and the noise you see can not be filtered IMO). Can it be "snubbed" ? perhaps. But it looks like a too difficuly way to attack something which could be attacked by ...

Quote
Peter, are you able to experiment with capacitor banks after the SMPS?

well, that. So *if* I am right, simply that would be the solution.
The other solutions should merely be about the "spitting noise" again, and while we (or I) always thought about that as being a culprit, look again at the picture. How can it get even worse ?
lol

Anthony, I think it was before your time in this forum, but at some stage many people bought a PCI card with a capacitor bank on it. Various capacity banks actually. I did too. Here : PCI supply rail noise (http://www.phasure.com/index.php?topic=2551.0). I forgot what was (sounded) wrong with it, but I rather quickly removed it. The reason will be in that topic somewhere (what about close to the end).
Anyway, it mattered for sure and possibly (as I can reason out only today) these caps were (dis)charging too slowly (they're not under load really). So it is blob here and blurp there and with all of them together just *because* it happens to slow, it wasn't random enough. Say a 100 times per second with all of them, and then not randomly (5 "fire" withing 10us of each other, then a few single with not equal intervals, etc.).
And of course back at the time we only thought about influence via USB. Per today they just surge the mains. Haha.

It's all a bit of a crazy thought.

Peter


PS: No AC snubbing in the NOS1a (but try if you like).

PPS: Don't forget what we look at below. This is through air. So that in itself is bad of course. But just practice (over here at least).



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: manisandher on October 05, 2015, 07:00:12 pm
I regard myself to be the loudest shouting person on the Net that a Linear PSU for an audio PC, WORKS. It works so d*mn good that now I don't understand why nobody is shouting about it. And yea, Mani, I know, you "admitted" that it works for you too. But you are the same as the so (really so) many others who obtained the Teradak - initially you are just too quiet. Or anyway quiet enough to not remember any hurays.

Nah Peter, you're wrong. I didn't shout about the Teradak because there were so many other changes in my system at exactly the same time and I couldn't attribute the obvious increase in SQ to just the LPS. Although I didn't have much time to listen to the system over the summer (just after all the changes), one thing I was sure about was that I was finally content with the sound I was getting. I mean, how long did it take me to upgrade to 2.02?

Oh, and I'd been using a Paul Hynes linear power supply with the PC I was using to make recordings (with the PMII) for I suppose over 4 years. At the time, I definitely shouted about the difference between the PH LPS and a SMPS.

Mani.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: CoenP on October 05, 2015, 10:45:14 pm
Hi,

I would definitely NOT put a capacitor bank after the SMPS. Only the wiring to and from the bank in conjuction with capacitor parasitics would make a resonance horror scenario. The SMPS is certainly NOT designed to take a large capacitance as load. I think that exactly happened with the 'capacitor buffer' PCI card that totally worked counterproductive.

Large banks are ok for dc smoothing in linear supplies provided that the transformer and diodes can keep up charging them. Mind you that all regulated supplies assume a distinct capacitance at their outputs for proper operation. That means that sq change as result of extra capacitance at the regulators output is likely yet an improvement Less so.

This is not a new territory. In the pre cambrium of computing all computers used only linear supplies. You can still find the big, big, big 'computer grade' capacitors you cound at the dumpstores. Also overclockers are fond of linear supplies because they are rumoured to allow for even more cpu juice at lower temperatures.

I've personally made a simple wiring change in the computer that made my LPSU (HDPlex) setup leap forward in SQ to an unsuspected level. I'd rather focus on the aspect of proper currentloops and creating the lowest noise by optimizing wiring than extra capacitance.

Regards, Coen

P.s. i found win8 and w10 also to be quite similar, but that was on the same pc with identical parts and setup. Yet I still favour win10 over 8, and win7 over them both.



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 06, 2015, 09:53:44 am
Thank you for your input, Coen.

Btw, I think you purposedly mentioned the capacitor bank AFTER the SMPS, which in my view would be in the DC path. But I envision something "in front of" (AC) and now I am not even sure whether that can work.

Anyway it should be clear that if the SMPS responds too fast to our likings, that nothing will change about that when the smoothing happens after it, hence now looking backwards : from the demand (MoBo etc.) towards the supply. All what will happen in that case is something for the far worse, assumed that the caps imply larger surges (at recharging) than the MoBo (etc.) does (though via many small "input" caps there, of course).

Otherwise I did not bring up the idea really, because I feel it just won't work because all is too slow now. However, not sure at all. But envision a processor in idle state (say consuming 20W) which within 0.000001 (just a very small number) seconds goes to 100+W. The SMPS is made for that quite explicitly with all kind of sensing whether it can cope (and when not, the SMPS shuts down the system (roughly put : cuts the power)).
I think this is also why such a supply runs at a high "sampling" rate (control loop) of 100KHz or whatever, so it can respond fast enough (with the notice that I really don't know much about it - which you already noticed :)).

Both solutions (SMPS and LPSU) work, but when with the SMPS the large buffers are in between the supply itself (say that control loop) and the consumer (MoBo) then all will be quite out of order because the control loop logic will look at the charge rate / demand of the capacitors. And the larger they are, the worse (slower) it will work (for proper control). It is just not made for that kind of operation.

So put the caps in front (AC) ? maybe that can't work either. I mean, I can imagine that the demand the SMPS can create (with it's speed of doing so) is too high for a too slow capacitor(s). But here again, I just don't know much about the working of the SMPS.

Feel free to debunk this all !
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 06, 2015, 10:15:49 am
Something else :

Yesterday the only thing what changed was the LPSU being removed of the chain and the SMPS back in. I did not change anything else, meaning that also the same wall outlet was used, thus with mains earth connected.
W8 also remained.

Horrible far away flat sound.
Luckily I didn't have more than 20 minutes of listening time anyway.

Of course this "test" was important, because it could have theoretically been so that suddenly my PC required mains earth in general (because of whatever other unnoticed change) and the whole rave about the LPSU was a hoax(ed thing).

But I have a very important message for all, again :

Any normal human being, never mind him or her being an audio freak, would right away state by means of this test that the SMPS can go to the trashbin and the LPSU is Walhalla.
Well, non-sense !
All I need to do is put the PC out of mains earth and all will be fairly normal. Use W10 instead of W8 (in the testing throughout) and the difference will be minimal, though the LPSU situation will win.

Anyway, that hard is comparing.

And was I ready ?
No, because while with the SMPS it is W10 which wins, with the LPSU it is W8 although again the difference is marginal.

... And that counts for my system ...
(although often people will be able to mimic the situation as I have it - as history testifies)

Tonight I will be using W10 again in the situation I was used to, and see whteher I can survive without LPSU.

Regards,
Peter



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 07, 2015, 07:01:59 am
Well, how did it go Peter?  Can you do without a LPS?


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 07, 2015, 11:16:44 am
Haha

I must be a complete nerd by now ... :yes:

As said, Windows 10 shows a tad of grey, although not many people will really notice. Anyway I do, and this is already because it's a character in the sound (of all). This disturbs me as I want all to be perfectly (??) neutral.
So yes, it was back to that again, and it is apparant because that was not the case with the LPSU.

The nerd part springs from here :

Just *because* I now knew how W10 can sound, and which is with more snap, not grey, more sprankle, I could see through my own settings possibilities and what to do to obtain that same sound. Sounds easy, and of course I only hoped for it, at first.
I came to this idea after an hour of playing or so, hoping that the (now) disturbing sound would have gone away with things getting warmer (ok, knowing that 20 minutes of playback is sufficient for that).

I was deliberating my purchase of an LPSU, meanwhile thinking about your efforts, Anthony, and how I could survive or again get used to what I had been used to for by now close to 3 months.

My SFS had been at 12 for the past weeks, coming from my more common 4, but remembering what ~ happens when I'd dial in 0.2. I try this some times, because I found that the Wallpaper Coverart shows normally, which otherwise (SFS at 4 or higher) is sometimes problematic in the RAM version of W10. Yes, somehow.
But that 0.2 never lasted for long although I forgot a bit exactly why (but it can last 30 seconds before sounds gets stable (not "scratching") after starting playback).

Well, I did that know too (set to 0.2), "hearing" that it would resemble the LPSU better, in advance. And God knows why - that worked. No grey anywhere.
Again a 45 minutes later I changed it to 0.1, having in mind the limit (which is for me 0.06 or so).
Haha, way better again (and I never before tried 0.1 or lower with W10).

Watch out please, because I only listened to one certain type of music, and it doesn't tell a thing about more normal music, like with voices etc. (they could be extra nasty). So this again needs more time.

The day after, I could try to reason out what actually happens, and it even seems possible to tell something about it. That is, since I the past few days was able to sort of figure out why the LPS sounds better than the SMPS, assuming the mains itself as the culprit (and not the computer interface or PC itself with now "better" power). So :

Well, when I was correct in my surging and too much spiking on the mains - the SPMS implying it, then lowering the SFS from 12 (or 4) to 0.1 is a simple 120 (40) times less spikey or 120 times more smooth if you like.
Point of course is that this reasoning equals that other reasoning (read : more chance to be correct with it).

This way of thinking is new, at least for me it is. I mean, so far it has always been about a too low SFS is skipping samples and things become more sharp (and pinpointed !) because of it, though while this is true, it is reasoning like a drag because this can only hold true for the very lowest SFS sesttings (say 0.08 and lower) because you start to hear it (I do clearly at 0.05 IIRC, although this is W8). But nobody is going to tell me that at the change from 4 to 12 to 60 you perceive a more and more "dark" sound because of less and less skipping samples. Thus no real explanation (up to the very end, I mean) in the losing samples reasoning.

This surging thing ... I like it and indeed it will work all the way of the SFS range (say from 0.1 to 470). It is only that once the SFS is somewhat higher (like 2) it becomes quite impossible to reason out what the OS is doing internally, hence is going to overrule my own software for being spikey.

Regards,
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on October 08, 2015, 10:48:07 am
As said, Windows 10 shows a tad of grey, although not many people will really notice. Anyway I do, and this is already because it's a character in the sound (of all). This disturbs me as I want all to be perfectly (??) neutral.

I notice that "grey" and it is one of the things that I want to remove with my playback...it needs to be gone!

The nerd part springs from here :

Just *because* I now knew how W10 can sound, and which is with more snap, not grey, more sprankle, I could see through my own settings possibilities and what to do to obtain that same sound. Sounds easy, and of course I only hoped for it, at first.
I came to this idea after an hour of playing or so, hoping that the (now) disturbing sound would have gone away with things getting warmer (ok, knowing that 20 minutes of playback is sufficient for that).

I was deliberating my purchase of an LPSU, meanwhile thinking about your efforts, Anthony, and how I could survive or again get used to what I had been used to for by now close to 3 months.

My SFS had been at 12 for the past weeks, coming from my more common 4, but remembering what ~ happens when I'd dial in 0.2. I try this some times, because I found that the Wallpaper Coverart shows normally, which otherwise (SFS at 4 or higher) is sometimes problematic in the RAM version of W10. Yes, somehow.
But that 0.2 never lasted for long although I forgot a bit exactly why (but it can last 30 seconds before sounds gets stable (not "scratching") after starting playback).

Well, I did that know too (set to 0.2), "hearing" that it would resemble the LPSU better, in advance. And God knows why - that worked. No grey anywhere.
Again a 45 minutes later I changed it to 0.1, having in mind the limit (which is for me 0.06 or so).
Haha, way better again (and I never before tried 0.1 or lower with W10).

Watch out please, because I only listened to one certain type of music, and it doesn't tell a thing about more normal music, like with voices etc. (they could be extra nasty). So this again needs more time.

The day after, I could try to reason out what actually happens, and it even seems possible to tell something about it. That is, since I the past few days was able to sort of figure out why the LPS sounds better than the SMPS, assuming the mains itself as the culprit (and not the computer interface or PC itself with now "better" power). So :

Well, when I was correct in my surging and too much spiking on the mains - the SPMS implying it, then lowering the SFS from 12 (or 4) to 0.1 is a simple 120 (40) times less spikey or 120 times more smooth if you like.
Point of course is that this reasoning equals that other reasoning (read : more chance to be correct with it).

This way of thinking is new, at least for me it is. I mean, so far it has always been about a too low SFS is skipping samples and things become more sharp (and pinpointed !) because of it, though while this is true, it is reasoning like a drag because this can only hold true for the very lowest SFS sesttings (say 0.08 and lower) because you start to hear it (I do clearly at 0.05 IIRC, although this is W8). But nobody is going to tell me that at the change from 4 to 12 to 60 you perceive a more and more "dark" sound because of less and less skipping samples. Thus no real explanation (up to the very end, I mean) in the losing samples reasoning.

This surging thing ... I like it and indeed it will work all the way of the SFS range (say from 0.1 to 470). It is only that once the SFS is somewhat higher (like 2) it becomes quite impossible to reason out what the OS is doing internally, hence is going to overrule my own software for being spikey.

Regards,
Peter


I love the way your mind works Peter.  You hypothesis seems valid on the face of things and it will be interesting to see where it goes.  The fact that you can ameliorate much of the influence of the LPS with software is exciting.

With the NOS1a noise should not be getting in via the USB cable, but could potentially airborne or via the mains or both.  But USB cables make a difference (this one I cannot figure out)!  Is there potentially another mechanism at work here via the USB, or are we hearing the effect of the USB via the computer back to the other modes of noise transmission?

 


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on October 09, 2015, 10:09:36 am
Hi Anthony,

Well, I like the fact that you are able to think along my ways. It encourages for some sparring (better : try to give it progress).

In about one sentence you suggest two important things for the possibility of explanation :

1. A similar noise pattern that may escape via the mains backdoor may also show its presence through radiation at the isolator (in-NOS1a);
2. A dedicated USB noise pattern may fold back (reflect back) into the PC environment and from there travels the mains path.

I tried to think of 3 and 4 (and 5 ?) as combinations of 1 and 2, but I think 1 and 2 contain all possibilities.

The point by now is, that once one is able to dig out the nuances and where to be for them, it gets more and more wild, but which for me means that I less and less understand what can be going on;

We can have "music" through our speakers or we can have super stellar sound (Q) exhibitions which are unheard.
Ok, that was not clear. Rephrase :

When we, like last week, go to an audio show and play all the in advance prepared tunes - which for me means a couple of years of collecting them - then none of them work. It just does-not-want-to-work. This means that none of it should be played, because it is total "nonsense". I use this phenomenon more often, because when you play something which doesn't seem to make sense for the reason of playing it, it is nonsense. Mind you, I am not referring to Jazz in the Pawnshop sh*t, which has its own life for some, and which will too play better or worse. But the worse will not be much noticable unless it hurts or something. Anyway, such a type of music always makes sense to some degree. And that I don't like a clarinet - can happen.

My "music" is that type of exhibiting a thriller. It was decribed by a visior of ours, a few months ago; it was the more rare occasion that we both enjoyed the exact same feeling and senses (bit of pun) while you actually are unable to see how it is done. It is so complex that it feels like it could only have been made possible in the artist's mind very explicitly, who next engages a bunch of synthesizers and hears back his explicit creation, but only because he knows what it oughts to do or be. Another one would not hear it because it is just too difficult to express it by the playback chain. It now is plain stupid stuff although some may bang their head on it.

In order to emphasize even more what technically is going on, without us being able to really see it : At that show we at first perceived sheer very explicit standing waves in parts of the room, especially in the back. You actually could not be there, that bad. But we knew that room and it could not be. So the analyser was pulled out and I saw an 11dB or so of too much noise. Mind you, still at ~ -130dB and it was totally inaudible (200W amps on 115dB sensitive speakers - no preamp or analogue attenuation).
In 30 minutes of time that extra noise was reduced to 5dB more than normal (grounding things a bit diferently) and I thought it was good enough.
No single standing wave anywhere any more and my partner in crime, Bert, could not believe that reducing that noise was able to diminish that enormous amount of standing wave. But it just did and without the experience you indeed are not able to believe it. But it is my hobby horse since about the start of XXHighEnd and a sheer measure. For me.

And still my demo material made no sense.
I just could not play it and instead we (ok Bert) reverted to Jazz in the Pawnshop.
What a drag ...

With some interruption of a Linear Power Supply, back at home all was joy all over, except for the first day when a connection to mains earth (or not) made the same difference of the world (but even worse than at that show).
Rephrase : best ever, once things were connected to the likings of the stuff itself. :)

Now the LPS is out, and of course I am sad; my reference has changed and I want to go back to that. An ever existing dial is changed and it seems even to have gotten better than with the LPS.
I don't need to play "demo" stuff to enjoy the meaning of ALL what I play randomly. Instead, all what I play just goes to the demo gallery, because it is so crazily good. And amongst them albums I sure played before and which were no good at all previously. Other people would ditch those - I save them for maybe better days.

So yesterday I had enough of listening to the very best and thought to change my SFS of 1.0 to 0.09. I could bare some ...
Restarted the track I just before finisned with the old settings, and already could not recognize it any more.
It got BETTER again.

Why this long story, seemingly unrelated ?
Well, because it is very related. :swoon:
About 18 months ago I create something with a silver or golden "a" and whatever I do in XXHighEnd, it does not change SQ. Today ? today it seems impossible that I did not perceive changes back then. But we must be careful, because since the beginning of the NOS1a, these things have changed :

1. New Blaxius Interlinks, including a full 75 Ohm impedance path;
2. New Clairixa USB cable;
3. The NOS1 I used for my "a" version was new and has a burn-in of 18 months by now;
4. New digital filters;
5. Windows 10;
6. OS fully in RAM only and no single device connected to the PC;
7. I experienced/learned a new reference (by means of the Linear Poser Supply), so I know what I can theoretically head for.

The effect ? well, where just over a year ago I needed to use some track with a seagull to let it fly through the room, now it hardly matters what I slide in. It is one big amazing experience.

And then after two says with some 1.0 SFS setting I try 0.09 and I can just as well start all over.

Ah, so what was I trying to say ?
Well, that unmeasurable things which even theoretically should not be there, make a difference which seems to be
impossible.

Radiation over an isolation ? can be. But if so, then apparently it can be influenced so wildly that something else (???) is even more wildly influenced in a fashion that is beyond me.

Surging noise on the mains, which is 230V to begin with and then influenced by a processor etc. which is performing a few instructions ? It is all veeeeery nice talk, but one must be totally crazy to believe in such a thing in the first place.

Still it is so that once I can make something consistent, it actually always leads to something for the better (sound) again. So I have to be the believer in the impossible and just go ahead with it, for even a year if required. Thus :

Nothing changed to my PC setup and if I today feel that it is mains surge what is happening, then a year ago that was happening just the same. However, the fact that I can assume this (surging) is happening is new, and with that knowledge I may be able to proceed and make progress again.

So now it is time for some software changes; long time in this realm, actually ...

Regards,
Peter



Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on November 13, 2015, 05:37:28 am
Well, today I sent away some files to China to get some pcb's made for an ATX Control Board.  This board will talk with the motherboard and manage the computer power supply accordingly.  It should be able to be plugged into the P24 socket of any ATX compliant motherboard and manage power on and shutdown procedures.  As an extra it has over-current , under-voltage and over-voltage protection for all the rails going into the P24 socket, but not for other rails for HSS/SSD, USB cards, cpu et cetera.  If warranted, these can be added at a later date but not to the ATX Control Board because it does not handle those voltages other than simply turning them on and off remotely via an AC mains relay.  This relay sits on its own little pcb and is controlled from the ATX Control Board.

So, hopefully I can get this to work first time round, and then the fun and games can begin as various power supplies are developed and trialled to sculpt the best sound.
 


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on November 13, 2015, 09:04:40 am
That is great news, Anthony !
I have my fingers crossed ...

Anyway hats of in advance. :yes:
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on December 02, 2015, 08:48:03 am
ATX Control Boards and Relay Boards arrived this week.  All the parts are here to populate them, but I am waiting on some transformers and heatsinks for the power supplies that these boards will control.  Hopefully next week everything will be here but in the meantime I will populate these boards and do what testing I can this weekend.

The ATX Control Board is all SMD (a first for me) populated both sides.  You can see the P24 connector that will got directly to the P24 on the motherboard.  The little single sided ATX Relay Board will go down in the first stage of the power supply (a separate box) and will switch the AC for all rails that are not 5V Standby.

The first power supply that I will build up will consist of 8 rails using LT1083/1084/1085 and TPS7A4700 linear regulators, often cascaded to get a good noise result by letting the first stage do the heavy lifting of the voltage regulation and then a second stage inside the computer with minimal voltage drop (and therefore heat dissipation) and hopefully some excellent low noise performance.

Once I get this all working, then I will build the really high performance supply using some newer but more difficult to use linear regulators to see if I can get a better result because of even lower noise.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on December 02, 2015, 09:00:16 am
:)


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: CoenP on December 02, 2015, 12:04:01 pm
Hi Anthony,

You worry me a little. I wonderd what you are going to use these regulators for, they are all 1-1.5Ampere max. Everything except the processor? The motherboard can draw some power on the 3,3V for peripherals and mind you that 1,5 A is only 5Watt. For harddisks and PCI usb cards the regulators you mentioned will be ok. Be shure to add sufficient heatsinking even when cascading.

I would use beefier LDO regulators or bootstrapped ones for the motherboard and processor (100w = 8Amps @12V). At these amperes you should have considerable heatsinking even with LDO.

My i5 PC consumes over a 100W on boot. When playing music the LPSU heatsinks get really hot in summer and it supplies less that 70Watt from the powerstrip (for 50 Watts that the pc uses). That heat comes from the 20Watt difference in input and output.

Regards, Coen


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on December 02, 2015, 06:10:50 pm
Hi Coen,

The LT1083/4/5 are nominal 7.5A/5A/2A respectively, so there is plenty of current available.  Perhaps you have them confused with other LDO's?

The heat sinking is quite something, and if the first stage is run at their maximum current load the LDO's will dissipate about 90watts between them, so I have two great big heat sinks on their way to me that should handle that load with a 20C increase above ambient, which in my experience will still feel quite warm.  There will even be two heatsinked diode bridges for high current rails.  At this stage I have opted for off-the-shelf power transformers and I really don't know what their temperature rise will be, but hopefully not too high.

Anyway, hopefully I can get the ATX Control Board to work first time.

Regards,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on April 30, 2016, 10:00:24 am
Hi there all and especially Anthony of course !

It looks like we're 2.5 years from the start of this subject and forum topic;
Right from the start I was involved but I never granted myself the time to really work on it, except for this one occasion where someone else was going to make an example for me, which up to date never got working (but I never hunted down the bloke who so-called could do it).

The last thing you heard from me regarding this was that I bought a Teradak on behalf of a customer - that it sounded better (which I already the next day equalled by means of other tricks), that it was going to be modded in Switzerland by yet another bloke who could do it, and while this is now, I think almost 5 months ago, two weeks ago I was notified that the PSU would be on its way back to me in two weeks of time. :yes:

In parallel Anthony took a lot of effort in trying out things, tinkering on how to make "a best", that ending up in a design and even physical pinted circuit boards, which btw is also from 5 months ago by now.
Also in parallel, but maybe not known (I forgot) is that our Juan wanted to set up a linear supply (by an acquaintance of him) which back at the time I thought was dangerous because nobody really knew what to expect and certainly not me. But, I should guide and test it. So I said No to that project and/but let Anthony proceed with his (how and why to stop him anyway).

Oh, that Teradak is of course still not back and when it finally is back it has to sound better than it did or otherwise that project (actually not mine, but that customer's) has failed massively.

Now guys, I don't know what it is, but if you all really take such a long time with it then it is only the wait for me to have actually quite other ideas and, say, outsmart all of "it". Not you (I wouldn't dare) but "it" as in : how we can approach all a little differently, sort of start over and find yourself with such few puzzle pieces that things start to work automatically.

Before I forget it, let me say this (in all honesty !) :
Anthony, I don't know whether something went wrong, or that you just "take your time" like all of this world around LPSU's seem to do (in the end including myself), but this is your last chance. I mean, if you don't have something ready for production (but say listening trials) Tomorrow, then I have something for that Yesterday. :) :)

And what a F*CKING GOOD SOUND comes from that.

(http://www.stordiau.nl/XXHighEnd PC/Phasure LPSU 01.JPG)
And what a mess it looks like. :grazy:

What you see in the front contains the LPSU but only two parts in the upper left and upper right corner plus the larger trafo. I can tell you that all fits in the PC you see in the back.
I can also tell you that the temperature of the "regulation" is 23.8C / 74.8F with an ambient temperature of 22C / 71.6F. And it is even playing ! 8)
But didn't I apply such trickery before ?

So you see, it *really* will fit in that PC, because it won't even get warm.



It looks like I got very smart and could work this out on a Sunday morning. But this is not true. It is the evolution of time and how week by week one can see things coming, try a thing, take a next step, try another thing, think a little, and decide for a final step (and now think this took years, say like Anthony's project also is (or seems) not finished yet for reasons).

The fun of this is also, that it requires references again. Thus, like the "sound" of the Teradak could already be superceded a next day with something else, there will also be merit in how that Teradak is overkill and therefore sounds "worse". I mean, I arrived where I am now by "steps" and each step showed its own nature of sound. Some weren't even the best and this is merely because of all ending up so totally black(ground) that there's too much "rest" as we say over here. One may like that, but that too implies a stuffed ear feeling. So it is a balance of black background and some "bite".
Furthermore I can tell you that power supplies to computers are as important to the sound as a D/A converter is and how software is. Possibly the PSU to the PC is even more important (says he who couldn't believe much of this in the first place).

The fun (for me) is that it is not the PSU on its own. It is a whole super big pile of all working together, in that PC housing. If one bit of it hadn't worked out, the LPSU in its current form would not have existed. If another part would not have worked out, the first part could not have been applied.
If XTweaks (which is software) would not have been created by me, we wouldn't even have been able to start thinking about what is happening today. Oh, Minimizes OS was ahead of it all, wasn't it ? Or maybe even Windows 10 is playing its little but crucial role.
ALL. Realy really ALL is required to let this work.

And yesterday it did.



It was even exciting, because at first nothing wanted to work, at the first attempt yesterday. No lights anywhere.
Found out that the voltage was 0.3V under par so that should be the culprit, but after changing that still nothing. This was a surprise because with a slightly (but 100 times more rough) different setup, all worked up to a couple of hours before. So what's up then ?

Remeasuring learned that no Voltage came from anywhere. Ah, ohh, oops, newbie mistake; the fuses in that general box had blown, which is a tiny little bit logical when they are 0.5A.

After they were replaced booting worked as before, but stopped when the display really had to do some work. This is how the video card ended up on the frame of the chassis (see picture).
Now it worked (and still does, now 14 hours later).

So, not 100% finished yet, as something was dimensioned just a little bit too tight. This is a pity because making "that" larger will again change the sound (yep, that's how it appears to work). But maybe I can be smart in some other direction; I already dreamt about a few things.

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on April 30, 2016, 10:10:23 am
Addendum :

I expect that questions may be asked which I maybe not like to answer (not in here and not by private email). I have decided - and tell it in advance - to just ignore those questions (that feels a lot more comfortable than saying that you don't like to explain).
This does not mean (at all) that questions are not allowed; of course they are. But I feel that I was able to create something which at this moment is unique and I tend to let it be like that for as long as it lasts.

Later we will see that much more springs from this, or at least can spring from this;
Suddenly there's a whole new "possibilities" world and all is of course for again better sound (yeah, I know, all stumbles over each other over here without ending up to you, but hey ... I always want the best sound of the world for a while ;)).

Regards,
Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: juanpmar on April 30, 2016, 10:41:47 am
Well, it seems that finally the long dream of getting a clean power for our Audio Pc approaches the end. Congratulations to the ones that have participated in it and also a special greeting for Anthony because his perseverance has also served to keep alive the idea that it could be done. Now we wait eagerly for the design, final adjustment and price.

Regards,
Juan


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on April 30, 2016, 11:34:27 am
Peter, that is great!

I have dropped the ball since the boards where built due to music room renovations and painting the house,  plus I have until very recently not been able to leave high voltage stuff unattended due to small kids, but all that stuff is behind me now.

I have managed to start and stop the pc with my board but that was all that happened before I put it away and did the house stuff.  Would be keen to share notes though...


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on April 30, 2016, 12:42:00 pm

Before I forget it, let me say this (in all honesty !) :
Anthony, I don't know whether something went wrong, or that you just "take your time" like all of this world around LPSU's seem to do (in the end including myself), but this is your last chance. I mean, if you don't have something ready for production (but say listening trials) Tomorrow, then I have something for that Yesterday. :) :)

And what a F*CKING GOOD SOUND comes from that.


Hi Peter,

I have a case laser cut for my supply sitting here that I will put together next weekend then I will install the power supplies and get it all working in a tidy fashion.  So by the end of next weekend I should have my first functioning ATX LPS operating and ready for listening and tweaking.  That is if you want to do something that way...it does not really worry me and you seem reluctant to share your ideas whilst I have a LOT of ideas that I am willing to share in the course of things.  I can keep a secret, you already know that.

I even have the parts here to build up another completely different supply of most enviable on paper performance plus I am working with a local Australian electrical engineer for something else that is a bit out of the ordinary...and probably something quite special based on the results other computer power supply tweakers are managing in my part of the world.  It is up to you Peter.  I will keep doing my stuff over here regardless of what you do there, but it will have less priority for me if we are not working in parallel.  After all, I also have my 6 channel single ended triode amplifiers to build soon of which I have the first channel on the prototype bench right now (440vdc...yay!) but if you are keen to move forward on this ATX LPS stuff, I am willing to put some priority to that from now on.

Let me know.

Cheers,

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: manisandher on April 30, 2016, 06:56:47 pm
As you know, I've been using a Teradak for coming onto a year now. I can't remember if it made a big difference in SQ because it was a long time ago, and also there were so many other changes to the system at the same time. I think it did. But right now, I wouldn't necessarily recommend it. Why? Well...

... how we can approach all a little differently, sort of start over and find yourself with such few puzzle pieces that things start to work automatically.

I can think of 2 ways:

1) Use an Intona to galvanically isolate the audio PC from the DAC. Run the audio PC from a different circuit to the DAC. Then don't worry about the PC's PSU - just use a good SMPS.

2) Give up on using an audio PC altogether. Use something like the new Sonore MicroRendu. I've just ordered one... but will need to use it with a Linux-compatible DAC for now  :(

Happy to have my ideas shot down.

Mani.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: AlainGr on April 30, 2016, 08:16:57 pm
Hi Mani,

Are you sure that you would need a DAC compatible with Linux to work ? Isn't a dac OS agnostic ? For formats like PCM and/or DSD ok, but not an OS ? :scratching:

Alain


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: listening on April 30, 2016, 11:50:33 pm
Give up on using an audio PC altogether.
Yes, we will see more of specialized PC designs.

Georg


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on May 01, 2016, 08:51:24 am
Happy to have my ideas shot down.

Mani, that is not all that difficult. None of such devices take into account what all can be done with a Windows PC (and Mac to a far lesser extent). So you are turning things upside down and only hope it works.
Nobody is working on such things to improve, say, monthly (make that yearly and it's still fine).

Let me tell you that once in a while you come up with these things because you (don't !) see that PC's can make things BETTER while you only think that PC's thus make things worse. This could be correct - but worse in comparison to what ? I mean, shouldn't you have gone back to the CD Player long gone by now ?

Quote
1) Use an Intona to galvanically isolate the audio PC from the DAC. Run the audio PC from a different circuit to the DAC. Then don't worry about the PC's PSU - just use a good SMPS.

Are you okay ?

Quote
As you know, I've been using a Teradak for coming onto a year now. I can't remember if it made a big difference in SQ because it was a long time ago

Oh ? The last time I suggested about exactly what was said in the previous quote and you told in reply that the Teradak for sure implied a big step forward. Actually that was in response to my suggestion it did not because you never talked about it. You then said exactly the same (similar) "yeah, but more things changed at the same time".

I recall that this forum should be about what we know for quite sure, and not what we like to say because of the moon phase.

Well, that was my way of shooting down ideas. Not explicitly, but please mind that you are doing this quite explicitly to the purpose of this thread. And *that* is what nobody likes, I'm sure.

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on May 01, 2016, 08:59:28 am
Anthony, I am still thinking of a nice response. I thought a good night of sleep would help out, but not really, yet.

Point is : All what I do changes vastly (or wildly) so I am just thinking about how to bring together our ideas in a "mathematical" fashion. So, I am on to again let produce PCB's because a certain regulator coincidentally does not fit on any of the boards I have, but doing it that way indeed takes ages. Plus, when I have it, I'll also have other things to do.

So I am just not sure how to finish this project, because I can be 100% certain that it can still take all kind of "tweaks" for improvement. And now how to do this together ...
(you can't even have my setup unless you spend something like 1500 euros, outside those PSU components)

?

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on May 01, 2016, 09:01:34 am
Another thing (to give Mani some right) is that to me it feels that now the day by day situation can even change more. In my ideas this can now be because all has been set up too lean (so to speak). So the leanness is good in itself, but now it is also more subject to washingmachinery.

Not sure at all, but unless my ears chang heavily daily, things do change easily.

Hi Mani !
:bye:

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on May 01, 2016, 09:07:14 am
And one other thing :

The improvement is so crazy that yesterday I was sure (again) that work needs to be done on the filtering. Well, at least it fealt like that (and people may remember that this happened before - I think when the Blaxius was introduced).

So yesterday I tried Arc Prediction. OMG ...
While previouisly it took some minutes of "sensing" which worked out for the better (Arc Prediction or the Custom Filter of concern) and it thus really was a longer term thing; now it is a matter of 5 seconds and you can decide.

It is really getting crazy.
We need "PSU Dials" !!
(oh, I have a new one in XXHighEnd already, especially for this)

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: manisandher on May 01, 2016, 09:30:46 am
... but please mind that you are doing this quite explicitly to the purpose of this thread. And *that* is what nobody likes, I'm sure.

I don't have a clue what you're talking about. But not the first time  ;)

I have nothing against using a PC for music. What I have a strong aversion to not knowing what the hell is going on - why the sound changes with a tiny tweak here and there. So, should we continue in this vain? And one answer is definitely, why not? Yes, it really is incredible how you keep making continual leaps in improvements. And you must know I'm one of your biggest fans in this respect. But maybe I'm alone here when I say I'm getting kind of tired of continual PC tweaking. I just want to listen to music...

Mani.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on May 01, 2016, 09:34:11 am
Ahum ... something else again ...

I expected something of it, but not quite this ...

With the normal Switching PSU I prepared that system to be as lean as possible, and it showed 29.5 Watts of consumption (this is where things start of course).

Then I applied the "normal way" (haha) of doing it with the Linear PSU, and it showed 45 Watts of consumption in the same state of the PC.

This one ?
This one shocks me a little because it shows 30.5 Watts. :swoon:

So Yes, I was aiming in such a direction (one has to take something for a mesasure to aim for, right ?), but this ? no, this is "shocking".
So the LPSU is only ~3.5% less efficient than the Switcher (which particular one is 90% efficient in itself).

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on May 01, 2016, 11:06:24 am
Anthony, I am still thinking of a nice response. I thought a good night of sleep would help out, but not really, yet.

Point is : All what I do changes vastly (or wildly) so I am just thinking about how to bring together our ideas in a "mathematical" fashion. So, I am on to again let produce PCB's because a certain regulator coincidentally does not fit on any of the boards I have, but doing it that way indeed takes ages. Plus, when I have it, I'll also have other things to do.

So I am just not sure how to finish this project, because I can be 100% certain that it can still take all kind of "tweaks" for improvement. And now how to do this together ...
(you can't even have my setup unless you spend something like 1500 euros, outside those PSU components)

?

Peter

Hi Peter,

I reckon there is a good year of tweaking to get the power supplies to their optimum, especially once all the options are trialled.

Not sure on what I would need to spend 1500euro...although this project has already cost at least that so far.

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on May 01, 2016, 11:49:53 am
Quote
Not sure on what I would need to spend 1500euro...although this project has already cost at least that so far.

At least that testifies that we both are crazy.

My side of the PSU endeavour actually starts at the 1.500 euros I paid for the non-operative PSU. Although ... today I could use it with some rewiring.

Btw, I hope there wasn't a burried message in your "high power and kids around is behind me" sentence.

Peter


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: acg on May 01, 2016, 12:23:21 pm
Quote
Not sure on what I would need to spend 1500euro...although this project has already cost at least that so far.

At least that testifies that we both are crazy.

My side of the PSU endeavour actually starts at the 1.500 euros I paid for the non-operative PSU. Although ... today I could use it with some rewiring.

Btw, I hope there wasn't a burried message in your "high power and kids around is behind me" sentence.

Peter


No,  the kids are ok... great actually... But I now have a dedicated bench to do this stuff so it is sooo much more convenient and I can do an hour or two in the evenings after they have gone to bed and I don't have to worry about shutting them out when the mains voltages are live.

So have you figured out an ATX startup and shutdown protocol for your supply? Or is it specific to your motherboard?

Anthony


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: christoffe on May 01, 2016, 01:50:04 pm
... but please mind that you are doing this quite explicitly to the purpose of this thread. And *that* is what nobody likes, I'm sure.

I don't have a clue what you're talking about. But not the first time  ;)

I have nothing against using a PC for music. What I have a strong aversion to not knowing what the hell is going on - why the sound changes with a tiny tweak here and there. So, should we continue in this vain? And one answer is definitely, why not? Yes, it really is incredible how you keep making continual leaps in improvements. And you must know I'm one of your biggest fans in this respect. But maybe I'm alone here when I say I'm getting kind of tired of continual PC tweaking. I just want to listen to music...

Mani.

Hi Mani,

the hobby on this site is similar to a F1 race competition.

Joachim


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: AlainGr on May 01, 2016, 01:51:42 pm
Maybe the FE instead (Formula "Electric") ;) ?


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on May 08, 2016, 10:42:17 am
Well guys, it seems that my project is coming to an end.

All now works for normal operation (so including video card and monitor connected and on). And SQ is still crazy.

What remains is some stress testing and see whether and how that holds.

Peter





Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: PeterSt on May 08, 2016, 02:35:08 pm
Stress tests passed too. All I could manage is let increase a couple of diodes with 25 degrees Celcius (from 45 Celcius (113F) to 70 Celcius (158F)).

:)

Stress test (the worst one) : Set CPU Ratio (BIOS) to Auto and boot into the BIOS. Now wait ... (all runs at full speed now).
Besides the fact that all could take it for the required current, after ~ 5 minutes nothing rose anymore for temperature.

:secret: No cooling fans anywhere.


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: christoffe on May 08, 2016, 02:42:32 pm
Stress tests passed too. All I could manage is let increase a couple of diodes with 25 degrees Celcius (from 45 Celcius (113F) to 70 Celcius (158F)).

:)

Stress test (the worst one) : Set CPU Ratio (BIOS) to Auto and boot into the BIOS. Now wait ... (all runs at full speed now).
Besides the fact that all could take it for the required current, after ~ 5 minutes nothing rose anymore for temperature.

:secret: No cooling fans anywhere.


Hi Peter,

sounds good.

Price & delivery time?

Joachim


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: pedal on May 08, 2016, 07:10:58 pm
Price & delivery time?

Joachim
Count me in too!


Title: Re: Investigating a full linear PSU for the XXHE PC and NOS1
Post by: manisandher on May 26, 2016, 11:31:11 pm
... how we can approach all a little differently, sort of start over and find yourself with such few puzzle pieces that things start to work automatically.
2) Give up on using an audio PC altogether. Use something like the new Sonore MicroRendu. I've just ordered one... but will need to use it with a Linux-compatible DAC for now  :(


Well, my initial findings are that the music server and player feeding the microRendu still affect the SQ. My hopes that PC tweaking would be a thing of the past have been well and truly dashed.

Mani.