USB to PC chassis ground ? (noise) - The biggest change ever !

[juanpmar]

Peter, I think you could very well write science fiction, a possible invasion of aliens, paranormal effects or how it feels when one is abducted by some alien force arrived from some unknown place.

Now I am traveling away from home for a week (again), but when yesterday I closed the door of my listening room, and let all those components in a gloom atmosphere, I felt that a new sound was waiting until my return, a new born and splendidly beautiful sound...

This all happened after isolating the card. What a great discovery, Peter!

Kind regards,
Juan

[Jack]

Had a similar out-of-body experience when I walked out of "The Doors" café last time I was in Amsterdam.......

[acg]

I'll have what you're drinking Peter.  No such thing happened here...not even close.  Are you able to remove the condom and see if it reverts?

Anthony

[PeterSt]

Jack, how was that ? I forgot somewhat. But something like "No Peter, can't visite you for some, and I rather be with my wife when she's buying new lingery.".
Hahaha

[Scroobius]

I think a new thread "Condom" is needed apparently they are good for hiding hallucinogenic drugs.

Paul

[Jack]

What with condoms, intoxicants & music, should this topic not be renamed Sex & Drugs & Rock & roll!

[AlainGr]

Wow... I am still trying to understand exactly the results. This time the stakes seem very high ! For the moment I am stuck with headphones but as soon as I get the chance, you bet I will check these results with the "isolated" card !

Alain

[AlainGr]

Strange question to ask, but at this point...

Should it be eventually a good thing to isolate the other PCIe cards around also ? Video card for example ? I don't have any rational hypothesis behind this, but ?...

Alain

[PeterSt]

Woh ! Video should be a foremost one. The monitor is THE most nasty thing in the whole chain.

Now let's see whether some condoms are left.

Good one Alain !

[juanpmar]

Strange question to ask, but at this point...

Should it be eventually a good thing to isolate the other PCIe cards around also ? Video card for example ? I don't have any rational hypothesis behind this, but ?...

Alain

Good question Alain. As still there is not any explanation on why or how the isolation affects the sound I guess that the best answer is try it and see what happens. I can´t do that but when I return home I´ll do it. I imagine that the same way that as less components are attached to the computer the better for the SQ, as more isolated are the components that are attached to the pc the better for the SQ.

Regards,
Juan

[PeterSt]

Are you able to remove the condom and see if it reverts?

Hohoho, watch out now; women could be reading this.

Anyway, so you really think that when I reasoned out something (which I did in advance) that I am going to cut off my beautifully coloured condom (same as Juan used ) and perform some A-B (which I don't ever do in the first place) because maybe I don't trust and my reasoning and my third leg - uhm, ear ?

Regardless of whether the bracket is in place or not I have a hum through my speakers that is only evident when I put my ear within about 10cm of them...it is standard transformer noise...and is evident in both the woofer and the tweeter.

So Anthony - everybody actually ... When do you finally get my message that when you have whatever audible "noise" from the speaker - no matter how close your ear - all is lost ?
I STILL must run into the very first person who can confirm "no noise at all !" and that for speakers which usually are 15dB less sensitive than mine (but can easily be 30dB less).

Compare it with all being bit perfect and we still can change the sound so vastly, in that software case through some software dials. Seems impossible, but is so.
This time the "issue" is different because it should impact noise directly and
1. PE becomes free of whatever USB Noise and thus doesn't influence the remainder of the gear;
2. USB is not polluted by PE anomalies which are all over the place to begin with.

Ad 2 :
2a. When the load on the mains changes, PE will change (DC Offset upwards) and because PE changes the neutral changes. And the other way around.
2b. The PC itself already changes the load all the time; watch your usage meter.

While this is all a bit outside of the subject of the quote, the message should be that whatever minimal (microscopic small) changes in noise and this time assuming analog noise not so much hammering on the digital interface (so this is my explicit thought) that in this same domain now YOU have analog noise of something like 70dB the very least (speaker sensitivity), while I have 20dB the very most. The calculation is a bit difficult to explain, but say that I know that inherent system (DAC) noise is -140dB, D/A conversion plus output stage is 20dB (I can see that) and the amp's gain of 20 adds 20dB of noise because the former 20dB is amplified. So it is about this middle part which I denote my "20dB at most". Really difficult to explain, but this is during playback at full scale (-0dBFS) while I attenuate 20dBFS at least (usually that is) which again brings the base noise level at -120dB (after amp gain).

Still there ?
That was a long way of telling that for normal playback my noise is at -120dB which is possible for you too. However, since you hear noise/hum this will be at least 72dB down (dynamic range of your ears estimated at 72dB, which story is longer again) and while "base theoretical noise" is at -120 and 120-72 = 48, the noise additionally produced in your system compared to mine will be 48dB.

If now only the influence I am talking about is in the analog domain indeed - and with which I mean that it happens in your amplifier and/or in the output stage of your NOS1 because of whatever groundloops, AND what I "influenced" with this change is bringing my own noise down with 0.5dB, than my noise has changed vastly (think like 0.5dB out of 20dB) while your noise changed relatively nothing (0.5dB out of 68 (20 + 48).
While this is one way to approach it, the other is to look at the resolvement of the bits for the NOS1, which coincidentally (or not) is at -120dB or 20 bits and that any 0.5dB (etc.) may just unveil that next bit. This, while though technically for your NOS1 it will be the same, practically it can not because your noise is at -72dB or more (because you hear it) or IOW 12 bits.
Do not underestitame this, because this is really how it works.

So, of course nothing of the sort happened in your system.
But notice my strict assumptions, which just start(ed) with the reasoning (first post in this topic). No way this was "USB interface" related, although there too it can have its impact - at least through analog means which is the PSU in there, which is connected to the mains (and now hammering on jitter again). But this is not the general idea.

Why not put up a test signal, and hook up your scope to the end of your loudspeaker cables. Focus on the haze of the signal you see. All sharp ? then digitally (!) attenuate until you clearly see it.
But of course you can leave out the test signal and just look at the noise. Next trust me that this noise will ride ON the signal.
Now you will get how all analog noise that is diminished a little (my 0,5dB example) won't bring you much. This thus, while in my case I am at the limit of the dynamic range of the D/A chip which is officially 110dB and I have 120dB already (but you too - that's just the NOS1).

This comes from your NOS1, 120dBFS attenuated (1KHz signal). Watch the noise level (around 30uVp-p) but also see how this noise curls around the signal).


All 'n all what happened here is explainable, if only it is allowed to think that an additional bit of resolvement can bring so much more. Whether *that* is true I don't know (yet) but obviously something has to explain it. Drinking a beer too many seems not feasable since I always first press play and only then flip the first crown (MMMV after that).

Lastly, please keep in mind that what I achieved for SQ here day before yesterday already is beyond anyone's leage as I see it. Not to show off, but to indicate how difficult it is to talk about audio instead of mutual listening, plus that I hear a few things more to begin with (because of it all being so good). But let's not make it difficult and instead simply refer to the hum and noise all of you guys have which makes me win all games here to begin with; only if you have the noise at the same level as I have, we can really start about amplifiers and speakers and who might now "win" because of the better amp etc. But even that won't be easy, but at least it is something of which I won't say "can't exist".

I hope this is helpful; it is to see whether I am really correct on all this.

Peter

[phantomax]

Strange question to ask, but at this point...

Should it be eventually a good thing to isolate the other PCIe cards around also ? Video card for example ? I don't have any rational hypothesis behind this, but ?...

Alain

I am wondering about that too. I steal the analog signal from the soundcard with its correspondent ground wire near the DAC chip, but the card itself is attained to the PC chassis in the usual way. I'll give a try when I feel brave enough (or at least less lazy).

Maxi

[PeterSt]

Guys, some will know about this already, but in brief the below quote (from elsewhere in the forum) tells what the actual objective is of me, right from the start I began with Phasure. Of course I want it to be happening, but it looks like I now really have it on its tail ...

[...] And an LPS (Local Positioning System). Sometimes I tell about this, but this has always been outside the real subject, and the subject were these trains. So, what I have been working on for a year or three together with a friend (all through email) was an LPS with 0.1mm accuracy. This was done through hyberboloid math (not hyperbole which is easy) and which could be done by 5 persons in the world. We could do it too my means of "stealing" examples through Google. The workout of the formula was (is) 14 pages of Word document.
We built a prototype which worked with (40KHz) audio and the real thing (light wave) was never done, but could have.
I stopped the project and started doing other things ...

Point for here is : all could be controlled by two antennas which could locate in the 3D space. Yes, two antennas. But with the smart addition of using different frequencies.
This is where the name "Phasure" emerged and where I was - and still am - quite sure that this principle can be reversed : use two speakers and locate the source in air again, the different frequencies taking care of that. One thing : it needs way more accuracy than audio (audible waves) can do. So for example, where the audio proto could achieve 10cm accuracy and while the lightwave same principle and software did 0.1mm, the difference comes from the short wavelength with light.

This is how I always try to make the audio waves more "thin".

[juanpmar]

>Peter: I STILL must run into the very first person who an confirm "no noise at all !" and that for speakers which usually are 15dB less sensitive than mine (but can easily be 30dB less).

I said I had no hum at all but it was not totally true at the end. I listened more carefully yesterday with as much as possible silence around and I could heard a very low hum in the woofer. What I can confirm is that in my case the hum was much lower than before isolating the card. In fact the hum was almost inaudible even touching the speakers with my ear while before I could hear the hum from a few cmts from the speakers.

Juan

[PeterSt]

What I can confirm is that in my case that hum was much less loud than before the card was isolated.

All,

I hope it is clear that nobody says that you can get rid of hum or anything by means of this. It might (to some extend) like in Juan's situation, but no rules exist.
All is one stupid complex of the interconnected pile of things including what's on the mains itself, and for example when I received new amps the other day (coming with the speaker) I really had to dig again because of course it hummed.

Peter