dedicated mains earth

[Diede]

Hi,

I’m currently setting-up a dedicated listening room, and to get the cleanest current I’m installing a dedicated fuse box (Siemens KE) with silver connections and HiFi-Tuning Ultimate Silver-Ceramic fuses in order to get the least possible interference with other appliances in the house.
I’m also installing a separate mains earth directly into the listening room.

My questions is what to connect to the this dedicated mains earth and what to the general house mains earth?
As I have multiple mono amps per side (Hypex Ncore with switching power supplies) my thought was to connect them to the house earth (in order to get rid of any high frequency stuff), and to connect the DAC and audio PC to the dedicated mains earth.

Anyone any thoughts on this?

Thanks,
Diede

[PeterSt]

Hello Diede, my 2c :

my thought was to connect them to the house earth (in order to get rid of any high frequency stuff)

Yes, that is the logical thought and in itself good thinking.
However, it will be more devistating because of other effects;

When you have two separated earth pins (or other means for separate earthing) you will be able to measure the potential difference between the two rings. What you will see is this :

Side note first :
Each device connected to the mains, gives the earth a slightly higher potential. Thus, connect a 220V light bulb of 100W (and switch on) and the earth potential may rise 1V. Of course I make up this figure, but it gives the idea of what's happening.
In my further view this is related to "voltage rails" as in :
The mains provided to you is 220V (or 240V) which assumes a 0V ground potential. Thus because this ground is 0V, the 220V delivered to your house remains that (remains 220V). If now your ground potential rises with 1V, you've 119V left and besides clipping may occur (on the sine (sinus) of the voltage). Please notice that I did not really test / measure such things explicitly, BUT that I have seen sufficiently strange sines from my own mains to find explanations like this.
In my own house I have measured as much as 107V potential difference between the house ring and a clean ring (nothing connected). 107 Volts ...
(but just oer 50V is normal in my situation)
So far the side note.

Whether this is detrimental to to the shape of the wave form is not so important now. Far more important anyway is the 107V difference which exists between the two rings. And, nothing is the matter with that as long as they stay separated. But now you are going to connect the two rings ...

From experience I know that there's only a very low current flowing, but the point is : where you connect the two by means of you amplifier(s) over the interlinks being connected to the DAC (for one example), you are molesting the signal ground in the interlinks. So there's a 107V wobbling on that, and this is not going to work well.
Notice that the strength of the 107V, in my view, depends on the current vs the current of the signal but point remains that it is there for influence.
Btw, the other day I tested laptops with batteries and for the same reason that would not work out (at all); possibly I posted pictures of that. Thus what happened here is that my Audio Mains Ring received a ground potential because of its own usage (say 10V all together) while the laptop is on a different potential (namely 0V) and that implying noise which was super easy to measure. Several 10s of dB's.

I'll hand you this as Part I of my 2c response.
Peter

[PeterSt]

I only now think about this again. I will come up with Part II tomorrow. Apologies !

Peter

[PeterSt]

Part II finally ...

In my previous post I implied that the power amps should not be on a separate ring. Nothing should be, actually. But true, such a noise spitting amp (btw not only with switching power supplies but also with digital (sawtooth etc.) behavior) should not be connected to the audio ring indeed. But what to do once you have them anyway ...
(I have no answer to that apart from the obvious)

In my earlier PC & Audio days, for a same reason as you suggested, I had the PC on a separate ring. Wrong too, and easy to measure that. But for that component of our chain there's this :

Have that PC as lean as possible, maybe give it a linear power supply, and connect that to the audio ring. I measure nothing wrong from that.
The last part now is the music storage, which best is to be another PC;

That other PC, the Music Server, is connected to another ring. Whether the normal house ring ? I guess that is fine (I have again another separate ring+earth for that, but alas). Now the monitor (one of the worst beasts for audio (noise)) is connected to that PC too, while the audio PC is controlled over RDC/RDP. Nothing different from what we talk about all the time (lately). Mind you, while the two PC's (Music Server PC and Audio PC) are connected by means of Ethernet, this is a galvanically isolated connection. Thus the Music Server PC is not destroying the audio ring, also not with its connected monitor.

Summarized :

Audio Ring
- Audio PC as lean as possible and without monitor
- D/A Converter (connected to Audio PC)
- Power Amps (preferably no pre-amp)
- (connection to Music Server PC via direct LAN cable)

House Ring
- Music Server PC
- Monitor
- When wanted, external disks with switching supplies
- (Connection to Audio PC via direct LAN cable)
- Router, Modem, etc.

Peter

[acg]

Mind you, while the two PC's (Music Server PC and Audio PC) are connected by means of Ethernet, this is a galvanically isolated connection.

Hi Peter,

I do wonder just how effective the standard ethernet connection is at separating potentials.  In medicine "Network Isolators" are used to guarantee that a voltage potential does not build up between medical and non-medical components.   From Wikipedia:

A specific hazard stems from possible differences in ground potentials between network components, which when not properly isolated can result in a leakage current that can flow through the patient, which is dangerous, and potentially lethal. Such voltage differences can also arise through incorrect installation and wiring of network systems, electrical shorting within damaged cables and cabling, or shorting between damaged network cables and other voltage sources.

Network isolators work to remove this hazard, by electrically disconnecting medical devices from a network. Isolators may be used as network accessories, built into medical devices, or installed within a medical network system. Networks isolators should be installed as close as possible to the medical device in question.

An example of such a connector is here.  Can you see any application for these in our specific situation?  Perhaps the the next step of isolating the AudioPC entirely from the outside world?

Regards,

Anthony

[PeterSt]

Hi Anthony,

Doesn't seem wrong to me at all.

Maybe we must "investigate" what the leakage atually is. I mean, I only copy words from others when I "claim" that Ethernet is isolated (knowing that transformers exist at the end points). But for how much current ? really no idea (easy to find out I suppose).
I also don't think that Ethernet was invented for its isolation behavior. It just is so (or ?). And it thus will also be "to some degree" I'd say.

Perhaps the the next step of isolating the AudioPC entirely from the outside world?

Isn't it so that a linear PSU just does that ? (the remainder being isolated already, lately )

Regards,
Peter

[manisandher]

Yep, I've been using the Baaske ethernet isolators for years now. Not sure how one would measure their effectiveness though, other than trust the manufacturer.

In the Orelo MkII thread Peter asked:

What was going on that you had that audible noise going on (while it shouldn't) ? I mean, apparently you maybe thought I was kidding or whatever else that made you not believe me, and therefore you didn't attack the problem in the first place (never mentioned it either) ? I now mean : it is quite crucial for me to learn what it was that created this noise. For a next one and helping out ...

Well, I was using a PurePower P2000 'AC regenerator' to power the whole system. This is actually just a glorified UPS that some (e.g. 'Romy the Cat') say imparts an interesting affect on the SQ. I've never been particularly impressed with my unit, which I've had for, I suppose, 5 years or so now. And certainly the Orelo MkIIs are simply too transparent for such a unit - you hear all the cr*p that it emits from its AC outputs. And god only knows what it kicks back out into the AC mains that feeds it.

I now have the following AC setup:

PC System

house AC mains -> PP2000 UPS -> music server -> Baaske isolator -> audio PC

Audio System

dedicated low impedance AC mains line -> 15KVA isolation transformer (with dedicated earth bonded to Neutral output) -> PS Audio P10 AC regenerator -> NOS1a (with Intona USB isolator to audio PC) & Orelo speakers

This setup is totally overkill. It really is. And the ONLY reason I'm doing this is because I spent a fortune on my 15KVA isolation transformer and dedicated earth. If I hadn't, I would not be doing this.

But Peter, I have a question for you: why have the audio PC on the audio ring? Why not have it on the music server ring? The Intona gives galvanic isolation, and now no need to worry about using a linear PSU for the audio PC.

Mani.

[acg]

But Peter, I have a question for you: why have the audio PC on the audio ring? Why not have it on the music server ring? The Intona gives galvanic isolation, and now no need to worry about using a linear PSU for the audio PC.

Hi Mani,

You are the guy that can test this by reinstalling the standard ATX SMPS into your AudioPC.  I can't test it just yet but wheels are in motion for my ATX LPS...I have a custom case being cut this week in which to stuff it all and once that is done I will be able to test the ATX Controller PCB and then all manner of LPS scenarios.

But in the meantime, if you had some spare time, perhaps see if your AudioPC less LPS still performs at the same level.

Cheers,

Anthony

[PeterSt]

But Peter, I have a question for you: why have the audio PC on the audio ring? Why not have it on the music server ring? The Intona gives galvanic isolation, and now no need to worry about using a linear PSU for the audio PC.

Did you ever witness that bloke watching some gag, holding his breath for one tad too long, after that squeezing out the air with a blast ?



that was me a minute back.

Mani, I guess you are right. I just didn't think about that ...

Peter

[PeterSt]

Pfff ... I'm still thinking in a flabbergasted fashion what we could be overlooking. But I don't think there is anything ...

That plastic box could be more golden than we imagined.

[acg]

Maybe we must "investigate" what the leakage atually is. I mean, I only copy words from others when I "claim" that Ethernet is isolated (knowing that transformers exist at the end points). But for how much current ? really no idea (easy to find out I suppose).
I also don't think that Ethernet was invented for its isolation behavior. It just is so (or ?). And it thus will also be "to some degree" I'd say.

If we are in the scenario that you suggest (and I am in at the moment) where I have a dedicated low impedance audio only mains line that is separate to the rest of the house, and we are running network cable from those two/three or more reasonably unique lines there could quite easily I imagine become a significant difference in ground potential across the length of an ethernet cable from the Music Server to the AudioPC.

So if we have USB properly isolated...ethernet properly isolated...power properly isolated (LPS) then there is not really too much more isolation work to do other than obsessive compulsive amongst us to attack RFI.

At least that is how I am thinking.  I do not know enough to have any definitive answers.

[PeterSt]

Ok, when we are in the mood anyway ...

I forgot the exact reason, but many years ago I bought some line level isolators (there's a transformer in there). They go in between DAC and Amplifier(s). Coincidentally it was 2 days ago or so that I thought about those again.
Back then I rejected them because they measured not linearly, but God knows what was going on back then, including my measurement skills.

Thus, these things exist;
Apparently I am not good at this (soo obvious) stuff, so maybe others can think of a usecase for them ?

Peter

[PeterSt]

So if we have USB properly isolated...ethernet properly isolated...power properly isolated (LPS) then there is not really too much more isolation work to do other than obsessive compulsive amongst us to attack RFI.

Anthony, the more time it is to now attack EMI !
So I am sure it is high time to get myself a decent meter for that. We can suspect EMI to be all over the place with all this isolation stuff and it should be relatively easy to now attack *that*. But first we must see it ...

Regards,
Peter

[manisandher]

Did you ever witness that bloke watching some gag, holding his breath for one tad too long, after that squeezing out the air with a blast ?



that was me a minute back.

I tried to imagine this, but it got too scary!

Mani.

[manisandher]

You are the guy that can test this by reinstalling the standard ATX SMPS into your AudioPC.  I can't test it just yet but wheels are in motion for my ATX LPS...I have a custom case being cut this week in which to stuff it all and once that is done I will be able to test the ATX Controller PCB and then all manner of LPS scenarios.

But in the meantime, if you had some spare time, perhaps see if your AudioPC less LPS still performs at the same level.

Hi Anthony, yeah I could do this... and I will when I have time. Certainly with my current setup (both music and audio PCs on same 'dirty' line) I simply don't see the point in having an expensive linear PSU for the audio PC.

But what I will try first is putting the audio PC (with linear PSU) on the 'clean' dedicated audio line. I can't imagine how this could improve the SQ... but I can see how it might make it worse - no matter how good the linear PSU (and I think the Teradak is pretty good), it's still a PC that you've introduced onto the 'clean' line.

Mani.

[acg]

So if we have USB properly isolated...ethernet properly isolated...power properly isolated (LPS) then there is not really too much more isolation work to do other than obsessive compulsive amongst us to attack RFI.

Anthony, the more time it is to now attack EMI !
So I am sure it is high time to get myself a decent meter for that. We can suspect EMI to be all over the place with all this isolation stuff and it should be relatively easy to now attack *that*. But first we must see it ...

Regards,
Peter

There are a gazillion meters out there for measuring all kinds of stuff.  Is there any particular unit you have in mind?  I am keen to emulate on this side of the world.

[acg]

You are the guy that can test this by reinstalling the standard ATX SMPS into your AudioPC.  I can't test it just yet but wheels are in motion for my ATX LPS...I have a custom case being cut this week in which to stuff it all and once that is done I will be able to test the ATX Controller PCB and then all manner of LPS scenarios.

But in the meantime, if you had some spare time, perhaps see if your AudioPC less LPS still performs at the same level.

Hi Anthony, yeah I could do this... and I will when I have time. Certainly with my current setup (both music and audio PCs on same 'dirty' line) I simply don't see the point in having an expensive linear PSU for the audio PC.

But what I will try first is putting the audio PC (with linear PSU) on the 'clean' dedicated audio line. I can't imagine how this could improve the SQ... but I can see how it might make it worse - no matter how good the linear PSU (and I think the Teradak is pretty good), it's still a PC that you've introduced onto the 'clean' line.

Mani.

 

One thing that I can't place though is the operation of the RAM-OS in your system.  How has it worked for you?  It has worked very nicely for me but if it made a difference for you then something else must be at work given the arrangement of your components, the supposed operation of the Intona and the reason for development of the RAM-OS being to reduce PC noise but reducing current draw in the PC.

[manisandher]

More later Anthony, but for now I'll just say that I had the whole system running off the PP2000 when I first tried the Intona. I only received the PS Audio P10 last week and that was when I set up the 'clean'/'dirty' AC lines.

It'll be trivial for me to compare RAM vs. HDD with the setup as it currently is. I'll do this this evening. And if there is no difference, I'll start playing around with the settings in XX, starting with SFS.

In a way, after all these years of XX development, I really don't want the Intona (along with a dedicated AC mains circuit) to be the 'holy grail'. But if it is, it is...

Will be back with my thoughts later this evening.

Mani.

[boleary]

One thing that I can't place though is the operation of the RAM-OS in your system.  How has it worked for you?  It has worked very nicely for me but if it made a difference for you then something else must be at work given the arrangement of your components, the supposed operation of the Intona and the reason for development of the RAM-OS being to reduce PC noise but reducing current draw in the PC.

I hesitate to jump into a thread where I am not very knowledgeable, but here's an observation/theory I've had about why the RAM-OS sounds so fantastic: when running the OS from RAM both electrical and vibration induced noise are eliminated. Prior to my RAM-OS I've had my spinning HD and fanless Seasonic PC power supply outside of the PC case on isolation footers. This step has always had a significant impact on SQ. When I first used the unplugged RAM-OS there was something very familiar with the sound that I believe has something to do with not having a spinning HD inside of the PC case. However, unplugging the RAM-OS went one step further to improve SQ because now electrical noise was also reduced. Today only my PC power supply is outside of the case and I make very specific adjustments to the sound with the type of footer underneath it.

One more observation: maybe it's my imagination, but try putting a 3.5 HD, or some other object weighing a couple of pounds, on top of your featherweight Intona. Seemed to solidify the sound a bit here.

Brian

[PeterSt]

There are a gazillion meters out there for measuring all kinds of stuff.  Is there any particular unit you have in mind?  I am keen to emulate on this side of the world.

Anthony, by now I see what you mean !!

And that is only when looking at the meters not even knowing what they exactly measure.

When I try to find out that part (what do we want to measure) then besides running into Gamma rays and such, this looks to be relevant :
http://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.html
but doesn't "connect" to those meters I see passing by. For example : http://www.lessemf.com/faq-mete.html (this site is way larger than it seems).

The only thing useful I came up for myself so far, is that there's a difference between the radiating device that will require near field measuring (e.g. hold meter close to Intona to find its radiating levels and eliminate other radiation sources) and the badly influenced receptor (like DAC) which requires far field masuring (hold meter near DAC and see what's going on for e.g. a radiating Intona).
And then I am afraid I don't even make myself clear.

But it starts with WHAT to measure. That requires what's bad for radiation. And that's a bit more hard to investigate because most is about human body (penetration) stuff or ghost hunting otherwise.

Anyway I feel another project coming !

Peter

[Diede]

Thank you Peter (and others) for your elaborate response, really helpful.

A few more questions come to mind:
What about using an optical HDMI or DVI connection and leaving the monitor connected to the Audio PC, thus avoiding going via RDC/RDP?

What about using shielded cable such as this one: http://www.conrad.be/ce/nl/product/1031706/Stuurkabel-OeLFLEX-CLASSIC-110-SY-3-G-4-mm-Grijs-Transparant-LappKabel-1125503-50-m?ref=searchDetail
and connecting the shield only on one side to the dedicated earth?

I’m really interested in learning more about those ‘line level isolators’ which would allow me to put the amps on the house mains.

Best regards,
Diede

[acg]

A few more questions come to mind:
What about using an optical HDMI or DVI connection and leaving the monitor connected to the Audio PC, thus avoiding going via RDC/RDP?

What about using shielded cable such as this one: http://www.conrad.be/ce/nl/product/1031706/Stuurkabel-OeLFLEX-CLASSIC-110-SY-3-G-4-mm-Grijs-Transparant-LappKabel-1125503-50-m?ref=searchDetail
and connecting the shield only on one side to the dedicated earth?

I’m really interested in learning more about those ‘line level isolators’ which would allow me to put the amps on the house mains.

Best regards,
Diede

Hi Diede,

In my experience running the AudioPC without a monitor (and using RDP) is a better solution than using the monitor.  Think about the power draw of a monitor...it's more than the computer...and even if the monitor is one one ring and the AudioPC on another they are still electrically connected by the cable between them, so the noise has a direct path.  It is easier to galvanically isolate ethernet and usb (now) than HDMI/DVI/VGA etc., so when it comes to the AudioPC and a screen "you gotta keep 'em separated".

Cheers,

Anthony

[Stanray]

Today only my PC power supply is outside of the case and I make very specific adjustments to the sound with the type of footer underneath it.

Hi Brian,

Could you please elaborate on the footers you use underneath the psu?

I was planning to do something similar and even put the psu on the floor, but then I have to find/make longer wires.

Regards,
Stanley

[christoffe]

In my experience running the AudioPC without a monitor (and using RDP) is a better solution than using the monitor.  Think about the power draw of a monitor...it's more than the computer...

Hi,

During music replay in an “unattended mode” XXH shuts the monitor down (sleeping mode), so no power ....... and that should not influence the SQ, to my understanding.

Joachim

[acg]

In my experience running the AudioPC without a monitor (and using RDP) is a better solution than using the monitor.  Think about the power draw of a monitor...it's more than the computer...

The current version of XXHE (correct me if I am wrong Peter) does not shut down the monitor, it merely puts up a black wallpaper and the monitor is 100% still connected.



Hi,

During music replay in an “unattended mode” XXH shuts the monitor down (sleeping mode), so no power ....... and that should not influence the SQ, to my understanding.

Joachim

[christoffe]

In my experience running the AudioPC without a monitor (and using RDP) is a better solution than using the monitor.  Think about the power draw of a monitor...it's more than the computer...

The current version of XXHE (correct me if I am wrong Peter) does not shut down the monitor, it merely puts up a black wallpaper and the monitor is 100% still connected.



Hi,

During music replay in an “unattended mode” XXH shuts the monitor down (sleeping mode), so no power ....... and that should not influence the SQ, to my understanding.

Joachim

Hi,

maybe I'm wrong  I take another route via the "energy saving options", and the monitor goes into the sleeping mode, and then the screen is dead.

I'm not convinced with the route tablet - server PC - audio PC, because I made different experiences. Shutting down ALL network services at the audio PC creates the best SQ on my system.
Maybe the last comment is better to discuss in a different thread.

Joachim

[manisandher]

It'll be trivial for me to compare RAM vs. HDD with the setup as it currently is. I'll do this this evening. And if there is no difference, I'll start playing around with the settings in XX, starting with SFS.

Well, I actually started with the latter and played around with some SFS settings. Recently, I've settled on SFS=0.07 - really nice sound with absolutely zero hiccups. I set SFS to 10 and listened. The sound definitely changed exactly in line with what we'd expect - it thickened slightly, became flatter and lost the lovely sparkle.

So, SFS still matters, even with my two AC mains lines and galvanic isolation between them via the Intona. Exactly how SFS can still make a difference is totally beyond me.

Via the mains? Well, there is no way noise could be travelling back from the PC, through its linear PSU, through the PP2000 on-line battery regenerator (i.e. batteries always connected to the inverter), through the house's consumer unit, back to the AC meter, through the dedicated low impedance AC line, through the dedicated hifi consumer unit, through the 15KVA isolation transformer, through the PS Audio P10 regenerator to the NOS1a. No way!

Via RFI? Well, the NOS1a sits in my little 'vinyl ripping studio' in the basement. This has a Faraday cage built around it (or as close to a real Faraday cage as I could get - the mobile phone signal cuts out as soon as I enter). The everything else sits outside this 'studio'.

Through the USB connection? This seems the only explanation to me. So, perhaps the Intona and the NOS1a are still not totally immune from USB noise?

Thoughts?

Mani.

Edit: Something I forgot to mention but that may be important is that the difference between SFS=0.07 and SFS=10 was much less than I expected.

[Diede]

...and even if the monitor is one one ring and the AudioPC on another they are still electrically connected by the cable between them, so the noise has a direct path."

Anthony

Hi Anthony,

Thank you for sharing your experience.

For clarification, how do you see the monitor and PC electrically connected if we use an optical HDMI or DVI connector?

Especially if they are on a separate earth, and possible even on a different phase (I have 3 phases in triangle at my house).

Thanks,
Diede

[manisandher]

I just tried Peter's original idea:

Audio Ring
- Audio PC as lean as possible and without monitor
- D/A Converter (connected to Audio PC)
- Power Amps (preferably no pre-amp)
- (connection to Music Server PC via direct LAN cable)

House Ring
- Music Server PC
- Monitor
- When wanted, external disks with switching supplies
- (Connection to Audio PC via direct LAN cable)
- Router, Modem, etc.

So essentially, I just moved the audio PC from my 'dirty' mains line to my 'clean' mains line to achieve pretty much Peter's exact setup. And the sound changed for sure... in very much the same way as increasing SFS. It became fuller, but also flatter, less dynamic and with less sparkle. The 'groove' was missing.

There is no doubt that I prefer the sound with the audio PC on the 'dirty' line, keeping the 'clean' line solely for the NOS1a and Orelo speakers, with, of course, the Intona doing the duty of galvanically isolating the NOS1a from the audio PC. (Without the Intona, this is a massive 'no-go' as potentially nasty ground loops would be created all over the place.)

You are the guy that can test this by reinstalling the standard ATX SMPS into your AudioPC.  I can't test it just yet but wheels are in motion for my ATX LPS...I have a custom case being cut this week in which to stuff it all and once that is done I will be able to test the ATX Controller PCB and then all manner of LPS scenarios.

But in the meantime, if you had some spare time, perhaps see if your AudioPC less LPS still performs at the same level.

Well this now becomes very important IMO. With the audio PC on the 'dirty' line, does one really need an expensive linear ATX PSU? Might a good SMPS ATX be just as good, or even perhaps a little better? I will definitely try this... but not for a week or so at least. The only ATX SMPS I have here has malfunctioned. I'm sending it back to Seasonic because it's still within its 5-year warranty, but don't expect a repaired unit to be sent back to me for a while. (Also, I'm working out of the country all of next week.) Will report back as soon as I have a chance to try things.

Meanwhile, if anyone else has two *isolated lines, perhaps they could try my setup and report their thoughts.

Mani.

* Of course, my AC earths are not truly isolated - they can't be as there is literally 'earth' between them. I've taken some measurements between the shield of the input Clarixa to the Intona and the shield of the output Clarixa from the Intona. The DC resistance is 3.7MΩ. The potential difference is 0.345V. If there were no Intona in place, the current that would be flowing through the Clarixa shield would be 9e-8A. (Edit: I guess this is the DC flowing through the Intona.)

[christoffe]

Found this:

http://www.acoustica.org.uk/t/earth.html

[manisandher]

Hey Joachim, from the link:

Whilst a definite safety feature when used as designed, like all things electrical PME presents some risk potential for those tempted to idly bung in a 'hifi' earth. If the house supply is PME then idly adding a local earth spike in addition to the bonded neutral has the effect that your house could end up as the safety earth route for 10-100 houses in the area. For example in the case of a broken neutral elsewhere in area supplied by the same substation transformer the multiple bonding, and all the leakage currents from your neighbourhood's hundreds of bits of inlet-filtered equipment /SMPS now sees your hifi's earth. Do you still want to rely on your earth spike ?

The Right Way

There is nothing wrong with connecting a local earth providing that it and the earth cable connected to it through your house can carry such a fault current. If you choose to add an earth spike it can be done on a PME system but only in this way: it must be bonded to the (PME) earth bonding point at the consumer unit only, using a conductor of at least 16mm2

Quite frankly, I think it's clear that adding just an earth spike is pretty useless...

BUT...

This is not the case in my setup. I am using an isolation transformer and have my earth spike (actually a 3m long copper cylinder with electrolytes to ensure constant low impedance to earth) bonded to the Neutral output of the transformer. My earth acts as a true safety earth for only the dedicated line and not the rest of the house or neighbourhood. This is a totally different setup to the one described in the document.

I think the real conclusion is just leave the safety earth alone. (Edit: Unless you want to go through the hassle of installing an isolation transformer. But I wouldn't recommend it - see next post.)

Mani.

[manisandher]

Following on from the above post...

When I first installed my dedicated low-impedance AC mains line, 15KVA isolation transformer and dedicated earth (bonded to Neutral output of isolation transformer), I was disappointed with the sound. I had such high expectations, and they were totally dashed. On the one hand, the sound was 'cleaner' in the sense that there was less hash, but on the other the dynamics were compressed. I spent a fortune installing all this and was determined to find a solution.

My feeling was that the isolation transformer was increasing the impedance of the AC mains line, sort of 'slowing' everything down. The system simply couldn't keep up with the transients in the music. This increased impedance was perhaps creating a modulation effect between the amps and the NOS1a. So the solution was to have some device sitting immediately after the isolation transformer to decrease the impedance. It would have to have some sort of store of charge in order to do this. I went for a PurePower P2000 battery regenerator, with a large SMPS and class-D output.

The PP2000 definitely improved the dynamics. I was right! But... it also added a tremendous amount of noise to the system. And you can't do this with 118dB sensitive horns. So I switched back to just powering everything off the house mains, and really the sound was pretty much the same. All this expense for absolutely nothing.

But then I had the idea that a good AC regenerator with linear power supply and class-AB output. The obvious contender was one of the PS Audio units. Because the objective was to reduce AC impedance as much as possible, I went for their large P10 unit.

And the sound has been transformed. Exactly how I expected it to be when I set off on the dedicated AC mains journey.

Was it all worth it? Up until a couple of months ago, I would have said no. I think sticking to good old house mains is OK. This is how Paul (Scroobius) is currently powering his system, and it sounds bloody good.

But with the introduction of the Intona, I now feel having a dedicated AC mains line for the NOS1a and amps starts to make a lot more sense. If you want to isolate the dedicated AC line as much as possible, then you'll need an isolation transformer and impedance lowering device. And now things start to get very expensive, and perhaps not worth it.

Just my thoughts...

Mani.

[acg]

...and even if the monitor is one one ring and the AudioPC on another they are still electrically connected by the cable between them, so the noise has a direct path."

Anthony

Hi Anthony,

Thank you for sharing your experience.

For clarification, how do you see the monitor and PC electrically connected if we use an optical HDMI or DVI connector?

Especially if they are on a separate earth, and possible even on a different phase (I have 3 phases in triangle at my house).

Thanks,
Diede

Might not be a direct electrical connection, but it is still there.  I remember the Adnaco optical usb solution that promised so much but delivered so little...the theory as to why that did not work is that it is the conversion from optical to electrical that creates the noise.  I personally would not bother with it for a monitor...the RDC solution that Peter has worked into XXHE is the optimum arrangement.

Think about it this way...at the moment I am using a cpu without an inbuilt gpu...and I am not using a graphics card either (it's just not in the case) so my AudioPC has zero ability to output a graphics to a monitor...and it is the best sound I have ever had.


EDIT:  I have two XXHE computers here that are identical apart from the cpu:  my Xeon and the other i7-3790K (I think).  On the face of things and without putting too much effort into finding a reason why, I noticed that my Xeon cpu sounds better than the i7 and I think that may possibly be because the Xeon does not have inbuilt graphics whereas the i7 does.  I really do need to listen further to this and make a definitive judgement, but those are my preliminary observations.  Maybe I should do that this coming week.

[PeterSt]

Hi Anthony,

It is the 3690K in there and it has no built in graphics.
But mind the difference in clock speed of the CPU's in both cases. Maybe there's a difference there.

Regards,
Peter

[acg]

Hi Anthony,

It is the 3690K in there and it has no built in graphics.
But mind the difference in clock speed of the CPU's in both cases. Maybe there's a difference there.

Regards,
Peter

Oh well, next theory then.  Will do some better comparisons next week.

[toddn]

So I had a thought/question.

Here in the US, we have two 120v hot lines and a neutral. So generally we have all our consumer electronics run off 120v and the feed is inherently unbalanced. In my current situation, there is really no reason why I couldn't run everything at 240v(either selectable input voltage on the equipment primaries or easily modifiable solutions). I would then have 2 hot lines and the ground tied to the neutral, so a balanced circuit.

Wouldn't this be a preferable configuration?

[DickieCornell]

Hi i am new here and also looking to install a system.
Can you please tell me about your Siemens system, what are its specifications?
Also what are the specifications for your DAC?
What is the need of the fuses for the tuning, please clear me this concept?

[ Moderator action : Removed spam ]