When you get your system up and running Rakesh, I suggest that you wait a while for everything to run-in, for the NOS1 takes a considerable time to come fully on song, and for you to to get used to the sounds that you are hearing and then change the standard computer power supply for an ATX LPS and let us know what, if anything, you hear.  Perhaps by then someone else has something good to report about their experience with this or a similar product and we can get some consensus.

I am more enthusiastic about the way that Phasure develops or gets things done than the ATX LPS project itself.  I am honestly expecting Peter to come up with something else, perhaps this w10 on ramdisk thing, that will mean that my project is not so important anymore and that there are other avenues to explore first.

We will see!!

Hi Rakesh,

It is not even really about the "conflict of interest" even if there really is one, which I am not sure. 

The way these things generally work is that someone comes up with a tweak, say the HDPlex LPS, and if they have a computer setup similar to the remainder of the group then some others will give that tweak a try for themselves and report in and if there seems to be some general consensus then perhaps that is the time to get excited by a group buy.  Certainly not before.  If we had a group buy for every perceived tweak all of us would be broke and have a garage full of useless contraptions. 

Truth is that most of the hardware out there is not applicable to the XXHE/NOS1a system although I can guarantee than most of it has been tried or trialled by one user or another.

Cheers,

Anthony

Hi Rakesh,

Just a little bit of history on this subject.  As far as I am aware Peter has an LPS that probably only needs a little more time to get working and then possibly he will bring it into production if it works out.  Personally, given the current direction and advancements Peter has made with W10 running from ramdisk I would wait for Peter.

On the other hand, Peter has sort of challenged me to get an ATX LPS designed and prototyped which I started in earnest some time ago and then set the project aside when the NOS1a and its increased immunity to noise from the PC came along.  Well just yesterday I ordered more parts to resurrect that project, and if successful I dare say that I will give the design to Peter/Ciska to build for all of us.  My design is more over the top than the HDPlex units seems...it uses modern regulators for a start...and the noise will be orders of magnitude lower than either the HDPlex or the other ATX LPS units that are available.  

Now, what we don't know is just whether these LPS will be useful or not and let me try to explain why.  What is not immediately apparent to many people that know Peter and visit this forum is that Peters approach is not necessarily to tackle the easiest issue first rather to tackle the issues that present themselves as being most important or limiting first.  An ATX LPS is one of those 'easy fixes'...you just make one then plonk it in your system and it does something good or bad or indifferent.  But what problem/s is/are being addressed by the LPS?  What issues does it cover up?  It is entirely probably that computer audio can be developed such that the ATX LPS has no effect on sound quality, and much, if not all of what Peter has done over the years with help from the forum is to work through ideas that probably shift/reduce/change electronic noise profiles so that they give us better SQ.  He has done this by trialling and choosing sensible hardware for the computer, designing his software to manage and manipulate that hardware via the windows operating system and producing a dac that is probably influenced less by the computer than anything else out there.  But the computer still makes a difference.  Operating systems make a profound difference.  It is frustrating, and would be more frustrating if the SQ was not getting better all the time.

So is it the right time for a ATX LPS for the XXHE PC?  Well, yes, I believe that it is the right time.  But like everything else that Peter does this ATX LPS needs to be designed to suit the current and future state of XXHE and the NOS1a/NOS2 dacs.  For me that does not mean using an off-the-shelf LPS that we have no control over and no input into its design.  Because XXHE and the NOS1a are already at the leading edge of computer audio, it is likely that it will need a solution that is just right for the situation, and we will need some experimenting to figure out just what it is about an ATX LPS that brings about any improvements and in that way we are more likely to reveal the next steps for improving things.

I hope I have written this in a way that is easy to understand...it has come out as a train of thought.  This also goes back to your other thread about building your own pc for XXHE.  I can almost guarantee you that if you follow Peters formula for the XXHE PC that you will be part of a rolling improvement in SQ as Peter and the forum take these incremental steps as part of a communal effort.  If you have hardware that is significantly different then perhaps you will miss out on some things.

Regards,

Anthony

Well, I'm 41, deeply afflicted by "the audio sickness" but my young kids respond brilliantly to music and when I put my 4yo daughter on the double-up pushbike and ride half an hour with her pedalling along behind me to childcare she sings and sings and sings.  That is the music that really moves me, and there are no electronics or rooms or speakers or even instruments...just a physical exertion with its endorphins and a gorgeous young voice making up songs as we ride along.

Anthony

Well this sounds absolutely fantastic!  If I understand you properly there is no easy way of getting past the pages of instructions that many of us will not be able to do without considerable help, but once we get there XXHE should operate pretty much as normal.  

If so, I can see why you think you will spend forever answering questions about why things don't work when/if we try to get this operational ourselves.  Can you think of any way around that?

Cheers,

Anthony

Peter, is the OS booting from/to RAM persistent?  That is, once it is done, it is done?  Or does the process need redoing every time you reboot?  I'm just trying to get my head around basically what it is exactly that you have achieved.

If I had to guess I would say no, you don't have to re-do it every reboot or after every shutdown unless you are relying on the W10 reboot procedure that saves stuff to RAM for quicker reboots to prepare the OS in ram.  Easier to say and talk about than to write.

But kudos.  I also spent a couple of days trying to get this done a year or two ago but was unsuccessful.

Oh, and I am offering to check your procedure here if you like...haha...serious.

You have my attention Peter.

Ha, I'm building exactly the same thing myself!  Those big horns are a LOT of work to turn, so in a way I am not surprised that it has taken several months so far for you to get them especially from an amateur builder (such as myself).  There is a mob in the US that make these for their horn systems and they allow three weeks construction for two workers...so one guy in a back shed is going to be much longer.

Peter, forgiving how ridiculous they can be but sometimes I think you need a like button on this site.  I would "like" both yours and Rakesh's posts.  If it ain't open and transparent on this site then it may as well be voodoo.  So please Nick, speak up.

Anthony

Interesting Peter.  Not that I have any playback at the moment but I am downloading the ISO just to have it.

I also would be interested in your opinions here Mani.

I occasionally drop in over there then I have nothing else to do...read some thread headlines...feel pretty sure I know what they will contain...and then go do something else.  Same ole same ole.

Part of what is holding people back from getting a great system instead of just a good one is because most of us are unwilling to learn all that it takes to do it, and are content to randomly sample gear or ideas or dogma until something clicks.  Guys like Peter that know enough to put together a high performing "system" and make it available as a turn-key unit are relatively few and far between.

Peter, so you are going SE amps now.  How does this affect the measurements?  The theoretical THD+N for the differential amps was less than 0.00003% and some premature measurements above showed values about a factor of 10 above that for the amps in differential mode.  Now this change to SE.  Are we going to get much more distortion, respectively speaking, at these already vanishingly low levels?

What really interests me (as you know) are small signals (say 1W) into high impedances (say 16ohm) because that is what will be in my speakers.  Most of the time I will be using well less than 1W.  There are available reasonably priced SS amps with 1W THD+N of 0.0003% which rises to 0.01% at 0.5W.  SS amps (such as yours) seem the be characterized by rising THD+N as the amplifier output (Watts) falls.  I think that it will be very interesting to see how your new amplifier behave at less than 1W.

Regards,

Anthony

EDIT:  Afterall, your top two channels are 119dB sensitive, so you will be using a fraction of a watt especially if you remove the passive crossover as seems to be the logical step with the NOS2.

Peter,

Would you expect noise to change when pushing say a 16ohm load?  Would be interesting to see the corresponding graph.

Anthony

Have you anything more to show us Peter?  Are the amps operational?