USB Clock Upgrade My Experiences (so far)

[acg]

Hi Peter,

I have been struggling to both comprehend and formulate a reply to your last big post for a while now.  My biggest issue has been getting my head around the many issues that you raise and my beginners perspective on them as well as trying to see the 'whole picture' so to speak.  I have a few questions that might put you on the spot but here goes.

Let's recall what I have always been saying : XXHighEnd is capable of influencing the DAC, and I know of no other means than that it influences the jitter in there (at the clocking out of the D/A chips).
I have also repeatedly been saying that I can not imagine that this is thermal or other noise inside of the PC doing that, hence that we're influencing the noise that travels over the USB cable. Careful, because the sort of fact that I can not imagine this, doesn't make it truth of course.

Could the pc noise also be influencing the analogue output stage of the NOS1 via ground loops (along with the dac clock)?  If my understanding is correct this would most likely show as a distortion rather than as jitter.

So, *everything* influences to begin with (in-DAC I now mean) and the best influencers will be those with a pattern, preferrably at the ms level or maybe somewhat higher. Well, USB transfer is per 1.25ms, so that's a good start.

<snip>

Anyway Anthony, when the noise sneaks into the data as you propose, you're suggesting jitter up to the degree of molested samples (but read missed and repeated) which in itself would imply more jitter than ever can be. This can theoretically be in order, but if so I wouldn't expect a better oscillator to sound better (for the D/A I now mean, so not USB). Btw, this can also be seen the other way around : how can a 200fs oscillator sound so much better than a 1ps one while all "scientific tests" indicate that we won't be able to perceive the difference. But alas.

I can follow this reasoning.  It makes sense.

So, I can not imagine that such a thing is the case (high noise in the digital data) *unless* this is again at the 1ms level which makes it happen once in the 1000 or so (768K) samples). Thus, jitter like 1ps is way more low than 1/768000 which allows for the 1/1000 not to be perceived as jitter but something quite else (higher level distortion);

We then could say that once per 1ms or whatever it is, we have high jitter for a very small fraction of time (something like the slew rate of the electronics) that possibly being so bad that a sample is missed or repeated.
And something like this happening once per 1ms gives a nice flair to the sound. Or practice : Once the 1.25ms USB transfer is visible at the outputs, this is perceived as more bass and blanketed highs. Easy to hear and thus easy to measure while this noise is say 135dB down (but rides on the signal).

hmm ...
Peter

This is where I am lost (I just don't know the theory) but I will take your word for it Peter.  Please don't feel the need to explain it to me.

In trying to make sense of this I have begun to wonder if there is improvement to be made by improving the power supply for the NOS1 USB board.  Is this something that you have trialled Peter?  I ask this because for the ATX LPS project we have some very low noise supplies that would be suitable for the task, and once they are built and tested perhaps I could try one of those.

Regards,

Anthony

[PeterSt]

Once the 1.25ms USB transfer is visible

I now see that I made a mistake here. This must be 0.125ms.

(more later)

[manisandher]

I don't really have the time to write in as much detail as I would like, but I'd like to share my experience of visiting Paul's (Scroobius) place earlier this week.

A few weeks ago, I asked him to take one of my two NOS1s and change the clock to a Dexa (and power supply). He completed this last week, and on Tuesday this week, I took my other unmodified NOS1 to his place to hear what the Dexas are really doing.

The standard, unmodified NOS1 sounded great, of course (using the mobo's USB3 port). [As an aside, I have to say that Paul has really hit gold with the rest of his setup - it's very, very impressive, especially the LF performance.] The 'clean', 'clear' sound of the NOS1 that we've all come to love is there in spades.

We then switched to the Dexa-modified NOS1 (using a Dexa-modded PCIe USB3 card in the PC). It became clear to me immediately that some sharp edges had totally disappeared from the sound. I wasn't really aware that they were there until we switched. The sound took on a 'wholeness' that is hard to explain. Much easier on the ear. Sweeter. But still totally detailed. It's almost as if the sound was 'pixelated' before and became a lot less pixelated with the Dexas. I had a strong preference for this sound over the non-modded NOS1 sound.

There is no question in my mind that Nick and Paul are onto something here. The Dexa clocks clearly change the sound of the NOS1 for the better IMHO.

But I feel there is one caveat though: Paul cannot use the Q5=1 setting in XX1.186 without his PC locking-up. I haven't played around with the Q-settings enough to comment, but it could be that Peter is able to replicate the effect of the Dexa clocks through software. This would obviously be brilliant... and a lot more convenient for us all.

As a final comparison, we switched to Paul's own NOS1. This has the Dexa clock and power supply mod (exactly like mine) but also has a bunch of Black Gate capacitors replacing many of the standard caps in the NOS1. OMG! The bottom end just 'explodes'. There's oodles of LF energy that is simply not there with the standard caps. A grand piano now has the presence that it does in real life, and no longer sounds like a small upright piano. I don't want to go into any more detail describing Paul's NOS1 because there may be some controversy here about changing the caps in the NOS1, but I will say that I preferred the sound of Paul's NOS1 to both my Dexa-modded NOS1 and to my standard NOS1.

Just wanted to share...

Mani.

[PeterSt]

But I feel there is one caveat though: Paul cannot use the Q5=1 setting in XX1.186 without his PC locking-up. I haven't played around with the Q-settings enough to comment, but it could be that Peter is able to replicate the effect of the Dexa clocks through software.

Mani, this feels like a joke. Maybe you missed a couple of 100 posts, but that Q5 (and 3 and 4) *IS* about mimicing this and it is 100% explicit.
So are you kidding me ?
Too bad that it is exactly Paul who can not use it. Maybe it isn't even coincidence.

*IF* Q3,4,5 can mimic what is happening, then I can wonder what will be happening to those Dexa implementations. At least it won't be the same, but I also can't predict what will come from it. That things just stall has slipped my mind but is a too long shot at this moment. I guess you did not try Q5=1 with your old NOS1 at Paul's ?
Otherwise let's take care that this topic won't be about Paul's problem; there is a topic for that.

Thank you for sharing this Mani !
Peter

[PeterSt]

well, kind of.

The bottom end just 'explodes'. There's oodles of LF energy that is simply not there with the standard caps.

Mani, I'd like to advise you the most strongly to let your other NOS1 untouched. You don't know what bass is. With your new speaker on the horizon you will though.
Now think of it; it is me who tunes the speaker and this is obviously done through what I have here and this is (also obviously) unmodded NOS1. If you guys "claim" that you can squeeze out so much more bass it will 100% sure (did you read ?) for the worse regarding your new speaker. OBVIOUSLY.
That it should be wrong in the absolute sense is something quite else, but there each his own (because each has another speaker with so many failures). Remember, I measure as well.

Hope this makes some sense ...
Peter

[manisandher]

But I feel there is one caveat though: Paul cannot use the Q5=1 setting in XX1.186 without his PC locking-up. I haven't played around with the Q-settings enough to comment, but it could be that Peter is able to replicate the effect of the Dexa clocks through software.

Mani, this feels like a joke. Maybe you missed a couple of 100 posts, but that Q5 (and 3 and 4) *IS* about mimicing this and it is 100% explicit.
So are you kidding me ?

Yes, I know you're trying to mimic the effect with Q3, 4 and 5. But the Dexas might still be doing something else too, no?

Anyway, once I get my modded NOS1 back from Paul, I'll be able to play around with the various Q-settings and see if I can replicate the Dexa-clock effect totally using the non-modded NOS1, simply through software. Again, this would be superb if it were possible.

Quick question Peter. Is it actually possible to take some measurements of the affect of Q3, 4 and 5 on the USB data transmission? Just wondered.

Mani.

[PeterSt]

Quick question Peter. Is it actually possible to take some measurements of the affect of Q3, 4 and 5 on the USB data transmission? Just wondered.

LOL. You really travel too much. I think this is all in this topic - 3-4 weeks back. But I can't do it - Nick maybe. But obviously not yet or otherwise he undoubtedly would have reported.

Regards,
Peter

[manisandher]

With your new speaker on the horizon...

Haha... I'll believe it when I see it!

No. I will always keep one NOS1 totally standard and totally untouched. Of course, I will compare the modded to the standard with the new speakers and decide which I prefer.

But thanks for the warning.

Mani.

[PeterSt]

Anthony,

Could the pc noise also be influencing the analogue output stage of the NOS1 via ground loops (along with the dac clock)?  If my understanding is correct this would most likely show as a distortion rather than as jitter.

That is beyond my imagination because of the too much influence "we" can imply. I mean, by now the difference (seen over XXHighEnd versions and/or PC Settings) has become larger than a destroying oversampling DAC vs the NOS1. And *that* can clearly be seen my measurement.
If it all is about jitter it would make much more sense to me although I'd still like to see this in similar measurements as just referred to. But *that* does not show at all ...

In trying to make sense of this I have begun to wonder if there is improvement to be made by improving the power supply for the NOS1 USB board.  Is this something that you have trialled Peter?

Not so much the power supply, but the whole "system" around the USB interface (including the USB interface itself). I have that (and running) but only partly and it can't be trusted for SQ merits at this moment. Btw, not working on that either.

This is a bit stupid maybe, but replacing the PSU itself could do wonders while I never tried. So, just put in such a main PSU (the one in the right leg) and done.
(not entirely true that I did not try because what I refer to above uses such a PSU).

I can only keep on saying that most probably we are persuing very difficult targets - at least difficult to try out because we don't even know exactly what we are doing while I can clearly see that a bit mangling with the software takes us further. In my view this does not count for things like replacing a PCI USB card like that Silverstone but I regard this as pure coincidence just as it is coincidence that for once *I* was the one coming up with something like that. It wasn't on purpose you know ...
Just as that it never has been on purpose that we all (without exception) started to use USB3 because it sounds better and one guy just tried it (two in parallel actually). Why it sounds better ? I always doubted it because I did not see the reason. I still don't but at least today we are way (WAY) further in the acknowledgement that this is an explicit field to explore.

The latter is the real answer to why I never tried a top notch PSU on the USB side. And how could I know. All *I* know is that I was the first (and maybe still the only one) who actually put async USB to hell because it implies the most jitter. Well, tackling that part was difficult enough. Might you have followed Mr Rankin throughout time, you would see him tell first that async USB can not "carry" jitter, next that his own DAC doesn't measure the best without clear reason, next that "hey, jitter seems to come through anyway without me understanding" (which btw is not true at all) to end with about today that he still doesn't understand. So, allow me.
Well, the latter maybe because Rankin wasn't the first with async USB no matter it is claimed all over the globe. Guess who ? (hint : the answer is not *that* obvious).

Anyway by now this is all from quite some years ago, and today I approach this all very differently; Just don't give anything the smallest chance to deteriorate at whatever level or part, no matter you think it won't influence anyway. And you don't want to know what it all takes to cover for this all. But some day ...

Regards,
Peter

[Scroobius]

The bottom end just 'explodes'. There's oodles of LF energy that is simply not there with the standard caps.

Mani you gave a very good summary and yes there is more bass energy but that is not the most important part of the bass story. I have spent literally months getting the bass of my system right. My big transmission lines generate a lot of bass energy and there are some big interactions with my room which is an absolute dog for acoustics. They needed a lot of love and care in room position, changes to the "stuffing" and crossovers etc.  Also obviously I have done a lot of listening whilst modifying NOS1.

IMHO the single most striking aspect of the bass now is its quality. Really this is bass of the highest quality it is tight fast & accurate. I did warn Mani that for many recordings he may even find them reticent in the bass - because if there ain't any bass they don't play it.

For sure I get fewer room interaction problems now with the BG's and that is counter intuitive given the "increased energy".

When Nick came down we walked around the room and the previous big room interactions are now much reduced. This absolutely is not just about bass energy.

Peter has made a very good point in that he has voiced the Orelo's with a stock NOS1 and we have to be careful.

Mani  -  obviously it is entirely up to you whether you want the BG caps installed but as I will be coming up to yours with the modified DAC we can spend time to find out which you prefer. We can try your other "Stock NOS1" (the joys of owning 2 NOS1's ha ha) compared with the modified NOS1. But also it would be pretty easy to move the Dexa's to your unmodified NOS1. So all combinations are possible.

It's good that you will be able to spend some time with the Orelo's and your stock NOS1 before I come along.

As far as Q5=1 is concerned I can actually listen to Q5=1 but it is also possible that I won't be able to stop it either and a reboot could be required.

The latest settings  6x10 1 1 1 &  120  Peter advised work well here and I can clearly hear the difference. But I have to say I will be very surprised if Q5=1 can do what the Dexa's do. But there again I have been wrong before (many times ha ha). But hey we can try it when I come up.

Actually it has to be interesting that I CAN hear the Q5=1 difference with the Dexa's installed.

Could be a long day.

Cheers

Paul

[Scroobius]

Peter,

I would really grateful if you would clarify exactly what you mean by

Too bad that it is exactly Paul who can not use it. Maybe it isn't even coincidence

I am sure I misunderstand what I think you mean by it.

Regards

Paul

[PeterSt]

Hey Paul,

I hope you got me right, although it would be an implied message : Totally nothing wrong with whatever and who wants to do. It's only that I will not be able to apply your Dexa('s) or caps or anything while making a speaker. At least not at this time (and as you'll understand can take years until all is sorted out definitely). So no implied "strange acts" needed from your side either. If Mani has that one unmodded NOS1 all will be fine always and indeed he can choose.
So, clear ? Yes.

Otherwise it is exactly like I tried to tell it; there is so (really !) much wrong in ALL of our chains, that everybody needs special attention or modding if you like. So it's only that I cannot anticipate on that all for a general product (that coincidentally being a complete system, outside the mains supply (sadly).

I hope all is fine.
Peter

PS: Paul, I'll hope over to your topic about your last post. Give me a minute.

[2glory]

Who in the US can do all these clock/BG mods.

Any of you Clock/BG modders want to holiday in Destin FL.? If so I can set you up in a beach house of one of my clients in exchange for work done on my NOS1

[PeterSt]

We just compared agendas here, and from of June 23 up to August 24 would be fine.