Yes,
My appologies Jim for going off at a tangent.

Regards,

Nick.

Peter,

To me more specific as you asked above. Jim's first set up uses disk access to read the music as it is played. The second using USB pass through does not read music from disk on the PC that is playing. I am by no means saying this is the main factor that would impact sound but is could be very relevant.

Regards,

Nick.

No problem Peter resect taken and you view understood.

So, the PC as a music replay device is broken period.

There still are mechanisms that link management of data in the PC which has been [is being ?] considered the data domain (think the school of thought that say it does not matter it just numbers being moved about) to the sound coming out of a DAC. Well how data is processed at hardware level in the PC DOES matter. In fact it more than matters, every single PC / DAC combo I have used for 8 years and those that I have herd elsewhere have had the same signature. I know now that this comes from the PC. BUT how data is processed and the timing of operations in the PC don't matter, it's just data that's what people would have you believe ?

Well if it's just data and how it is moved about doesn't matter then I need to get my ears replaced. In 8 years of listening to computer audio I have never heard such a change in sound quality. Reproduction now sounds more like music with real people enjoying playing together. It the single largest change in my system since moving to computer audio... And not finished yet 

It's too early for detailed theorising on line.  Although I will own up to having my nose in a too many very detailed papers. I am pretty sure that I understand the processes that impact sound within the PC now and to a point that it's possible to approach different elements of the PC with predictable outcomes. The element now being worked on is the disk subsystem as I said above and boy if these changes are not possible because it's "just data" I am delighted to live in a BS world and keep the sound quality changes thank you  .

The one point that I still cannot really pin point is how the linkage from the PC into the DAC audio domain happens. I have a good idea but it would be a great thing to understand this because the PC may be tuned even more or might is be possible to make the DAC immune ?

As mentioned a couple of times elsewhere the performance of the PC for music replay will impact PCIe USB and FireWire interfaces. IMHO this is not about the simply superb NOS1a.

Regards,

Nick.

Ha! I was a bit slow there.

Got you 

Nick.

Peter hi I agree, more likely to hear reduced hash is the highs not in the bass. I was typing a little too fast on a tablet  . Sorry for the confusion.

Regards,

Nick.

Jim hi,

Love the story about the ESL63s I certainly understand why you have had them so long. I also had a used pair form many years, I was so attached to them I could not bring myself to part with them for 5 years after I had bought a set of horn speakers. They do things others just cannot manage :-).

Thanks for the description of sound. Now I read your first post again I think the laptop playing music in the pass through USB mode maybe using its disk sub system after all to read the music data.

The playback setup is sort of smart with the dCS and word clocks, really understand where your coming from with the flying pig comment, you just would not think it would work  There is certainly a lot that could change the sound, word clock quality, over sampling algorithm or other things. Your post caught my eye because I'm looking at the PC's storage sub system at the moment. What you have described is the sound is sort of consistent with the PC's disk subsystem being improved or in this case perhaps removed from the replay chain. But again re reading your first post I think the laptop is still reading its disk but there are newly introduced SPDIF and upsampleing steps in the data path.


Kind regards,

Nick.

No not intensional  , just what changed with the sound ?

There is another large difference between the two test setups that is not being considered. Intermodulation of the two word clocks is going to have an impact sure but there is something else. Think where the data originates from in the two setups. Its very different in the two cases, there is a whole subsystem of the PC not being used when the pass through setup is being used. This really really matters :-).

Regards,

Nick.

Jim_f

For sure two word clocks will run out of synchronisation and buffer glitches must happen as a result at some point. I have plenty of experimental evidance of the impact on sound quality that relative clock speed in the replay chain (5 clocks looked at so far more on the way) has on sound quality. This is both within the PC in what would have been considered the data domain and withing the DAC itself.

My guess however is that the word clocks running at different speeds is a secondary effect here (unless the two word clocks are grossly out that is, think 100s to 1000s of beats per second out).

There is another significant difference between the two setups you have tried that is likley to be the prime reason that the sound is changed. It would be helpful if you can you post your impression of how the sound has been changed ?

Hash improved bass, clearer highs, more detail, dynamics ?

Thanks,

Nick.

Peter hi,
Yes I still have the physical connection for SPDIF, but of course not a live connection live now days.
Regards,

Nick.

Jim_F hi,

Great post and a result getting a recombined 192k stream into your NOS1a. I would be interested to hear what the resulting sound is like compared to playing at 192k directly to the NOS1a. Thinking about the end setup I have a hunch that the change might be due to both dCS up-sampling and PC. I am working on what might be  the related area in the PC at the moment so this is very interesting.

Is there any chance you could post thoughts on what changes in sound reproduction ?

Many thanks,

Nick.

Before things kick off too fast, I wanted to provide a update on where I think the PC upgrades are at right now.

Mani and Pauls systems have been updated with the first two modifications (well three if you include the USB clocks already applied). In addition headless configuration and a storage options for OS and XX are being used which IMHO also help (thanks Mani for pointing out the video card less configuration, one of those happy coincidences given what I was working on at the time )

There is however much more to do to prove the overall concept and finish this, already there are mods to Mani and Pauls configs I have in mind to test (I will apply these guys for you if they work here).

Given the interest I will try to accelerate the work.

Finally I would like to productise this approach, both as a retrofit and as a very high end music server. There is a very large amount of work to do to establish the complete spec beyond what was listened to last week end, already some promising results in other areas. Work has already begun on how this all can be practically implemented with some very neat solutions being considered.

Peter I'll drop you a note to discuss how I should handle updates or not were this to become a slightly more commercial endeavour.

Best regards,

Nick.

I hear my words being used here Paul. The Dexas have some unique features which may mean they may remain the gold standard for what has to be done to the PC. The rest should remain a private conversation for now please.

Nick.

Hi,

Turn my back for a day and wow this has gone a bit mad  , so many posts. So to catch up on a few points....




Mani,

Thanks for having the faith to commit to trying this out blind. It certainly works and takes transparency and musicality to a new level IMHO. I am very pleased that you are so happy with the outcome but to be honest knew that it could work it is in the no-brainer camp I think.

The point above is not one to be to be overly concerned about  I took my time with your PC. This would always have to be the case but if you understand what your doing these changes can be applied reliably and shipped safely without problem.

I like the idea that you may play digital music to your vinyl dealer when he comes round I can see how that would go unnoticed ! To your vinyl loving friend, the sound of your changed system could be as tempting as a bacon sandwich is to a vegetarian haha.




Joachim hi,

This is not quite the way that it might work but having given this some serious thought for significant period and doing work that has not been mentioned in these posts geared to this. There are a number of options that might be offered. Given my thinking I did smile when I saw this you will find out why in a later post.



Peter hi,

I actually think you absolutely right, your system does somehow do some of what my PC modifications do. It's funny you should mention this, my visit to yours some time ago got me thinking afterwards about a number of things, and the low hash quality of your system was one of them. How come your system had less of a hash problem than the others I had listened to ? Why did the USB clocks I bought along not work as expected, and bloody hell ,I never wanted to listen to those Patty Grffith  tracks again  
Thinking about the possible reasons there was less hash in your system, solving the USB clocks performance and focusing for long time on what the common characteristics of my previously rather large library of “problem tracks” all helped point the way to think about the PC.

I honestly don’t really have many “problem tracks left now and since changing the PC for some time have been actively selecting really difficult stuff to reproduce. The reason is because often its these performances that are seat of your pants raw and complex and on the edge in some way and this makes them riveting if they can be reproduced well.



Mani hi,

All setting matter again  but also  , I would say more so in some ways, even down to 0.1SFS and all of the other settings. This is consistent with the theory that is driving the modifications to the PC hardware.  Now the good thing is that it is no longer a case of having to used the XX software settings to “match” with the PCs hash signature to give the least offensive overall sound.  It is possible to find XX settings that just don’t have anything like to level of “compromise” . Previously I would be tweaking at XX settings almost every track in the hope of getting it right somehow, not now.

As we discussed I would really suggest that you start with Peter's BIOS settings and Peter's W8 software settings as a start point. I don’t think it is coincidence that in the comment above I mentioned that Peters system exhibited some of the qualities of the modified PC and that Peter settings hit a sweet spot with these XX Settings.

Happy tweaking this time, yes time to tweak again but this time I think you may get a satisfying sound at the end of it and not really need to adjust very often after this.



Paul,

I agree the match of the NOS1a and the modified PC is supper supper sweet however as I mentioned much earlier in the thread the modification to the PC should improve any system using Firewire, USB or PCIe interfaces to a DAC. On a case by case basis it is very likely that the relative change in sound quality the modified PC delivers with some DACs will be much greater than with the NOS1a. My view is that Peters 1a upgrade actually significantly reduced the susceptibility of the NOS to the PC's  "sound signature". In the back of my mind the objective has been to address the "signature" of the PC that we have all been listening to for years. I honestly remember the same hash signature, and as Mani puts it metallic quality, in pc sound when I first started with PC audio and moding M-Audio Transit Cards. so its very nice to see it leaving the sound at last 




Regards to all,

Nick.

Joachim hi,

It was a great meet up, Paul and Mani had chance to listen to what is happening here and I think got a good sense how these changes are moving the PC forwards. The listening included a number of problem tracks which have in the past seen my system really struggle to portray the music enjoyably.  I had spent a lot of last week adding some new components into the PC and tweaking the clock setup but as always seems to be the case, the sound was however significantly better on Sunday (the day after), more on this in a moment.

There was a very long session applying the upgrades to a PC which happened to be based on a mobo that is in current production, which is great. The results were very good indead, possibly better than on the ASRock Extreme 4M that I'm using. There were some measureable differences between the two boards in a key area. Performing the upgrades I spotted possible changes to my configuration regards how the clocks are connected. I tried these changes on Sunday and things improved significantly. I wish Paul and Mani had had the chance to hear this config, but that's the fun of these sessions, by trying things out you learn more.

Paul and Mani may want to post on what they heard here and also what has happened in their own systems since the visit 

Best regards,

Nick.

I have identified a correlation of the clock distortion with supply rail noise within the PC now. In addition to this another mobo (not the same as mine but with the same ATx supply) I was working on over the weekend showed only small fraction of the clock distortion.
This is becoming very interesting.....

Listening opportunity was very limited on the second PC, but it did sound exceptionally good immediately. There could well be a link here.

Nick.