Do I need clean USB power when using DAC with its own power supply?

[March Audio]

Just now, The Computer Audiophile said:

You're a perpetual line stepper. You know the rules of the forum, yet constantly step on the line. 

 

It doesn't matter if everything you said was true, people come here to enjoy this hobby and you continually challenge people just trying to have fun. That's why we have the objective sub-forum. Your crusade to save people from themselves and right every wrong in audio is what's offensive and not a good look for you or your company. 

No crusade Chris, just commenting on the subjects that come up.

 

If this is only about "having fun" why are you on a crusade with MQA?

 

By your comments here, it seems that MQA should just be allowed to slide by because the fact that it does nothing useful is unimportant.

 

Some people are convinced that it improves sound and you are "spoiling their fun" by pointing out otherwise.

 

Thats just hypocrisy.

[March Audio]

3 minutes ago, The Computer Audiophile said:

Have at it in the objective forum. You know this. Don't pretend it's censorship.

So a parallel thread for every subject because some here are incapable of reasoned debate and get offended every time some information contrary to their view is presented.

 

If thats what you insist upon.

[The Computer Audiophile]

43 minutes ago, March Audio said:

No crusade Chris, just commenting on the subjects that come up.

 

If this is only about "having fun" why are you on a crusade with MQA?

 

By your comments here, it seems that MQA should just be allowed to slide by because the fact that it does nothing useful is unimportant.

 

Some people are convinced that it improves sound and you are "spoiling their fun" by pointing out otherwise.

 

Thats just hypocrisy.

 

Because mQa takes something away from my enjoyment of this hobby. I no longer have access to some pure PCM tracks on Tidal. In addition, anyone is welcome to open a pro mQa thread here on AS and even moderate it him/herself. 

 

Now, back to you. I think it's time you take a break from Audiophile Style. You have your own forum on which to write whatever you wish. You also had the opportunity to write almost whatever you wish in the objective sub-forum here, but you couldn't resist jumping all over everyone in every thread. 

[The Computer Audiophile]

9 minutes ago, March Audio said:

So a parallel thread for every subject because some here are incapable of reasoned debate and get offended every time some information contrary to their view is presented.

 

If thats what you insist upon.

 

Has nothing to do with what people are capable of, it's all about what people do with their own precious free time. 

 

How about next time you go to dinner, you start telling people sitting at the tables next to you that they could've found their clothes much cheaper at a different store. Plus, they should've ordered a different main course because the one they selected isn't as good as the place next door because it has more calories, more fat, more sodium, and is more expensive. 

[Archimago]

2 hours ago, Rexp said:

You still don't get it, there are no measurements that correlate with the listening experience. You science guys have failed to develop the appropriate tech. 

 

I guess this is a fundamental disagreement here which I think is important to address.

 

What I'm interested in (and I suspect many "objective" types) is actually not whether any one person's listening experience is felt to be "good" or "bad". Subjective experience is simply the emergent property of that individual. It might not correlate with the impressions of others, and often it might not even be a function of the device's ability to reproduce audio with high fidelity.

 

Over the years as I've done stuff like blind tests whether in person or with some of the online feedback, it's abundantly clear that when we're talking about relatively high quality source material, subjective opinion is highly variable. For example, years ago, I ran a 16-bit vs. 24-bit blind test. Here's the subjective feedback:

http://archimago.blogspot.com/2014/07/24-bit-vs-16-bit-audio-test-part-iii.html

 

Notice that the answers run the range from something the likes of "hard to tell" to folks who were able to described stuff like "spaciousness" or "details". Then there's the person who basically did an ABX and found they were "50%" even though he/she thought there was a difference initially!

 

Despite all these subjective opinions, we clearly know what the difference is objectively between the potentials of 16-bits vs. 24-bits. Why should we even bother "correlating with the listening experience"? Whose listening experience?!

 

Assuming we have 2 high quality devices (a poor device will clearly sound deficient), I actually think engaging too much with subjective evaluation is a fool's errand without blinded comparisons. It simply triggers emotional insecurities, obsessions, and "what ifs?" that may not be true at all. Pair that with all the subjective talk in magazines and forums about how "awesome", perhaps more "hyped" some upgrade / cable / DAC / de-jitterfier / low-noise power supply / etc... might be and you end up with the risk for insecurities and becoming neurotic when one might have been better off just listening to music and enjoying it!

 

When I have a "standard" DAC (these days typically my RME ADI-2 Pro FS R Black Edition) and a "comparison" DAC side-by-side, then maybe I can make some consistent comments - but even then it's within the context of the whole system, room, ambient noise level, listener experience / hearing acuity, etc. 

 

Don't forget that also whether a certain piece of music sounds good for the "listening experience" is actually the domain of the artist and production team. I can have a wonderful "listening experience" from music played off the FM radio in my car with Bose speakers (yes, I have those ;-) as much as in some megabuck system demo. How we allow ourselves to emotionally experience the music is a whole other dimension which "hardware audiophiles" might also not talk about enough.

[Rexp]

 

[audiobomber]

1 hour ago, opus101 said:

 

If I were looking for a measurement to correlate with PRaT I'd be looking in the realm of noise and noise modulation. I have a Xindak amp which I modified the power supplies of and it greatly improved the PRaT - I figured noise on the supply lines (which may well have been signal-modulated) wasn't being rejected sufficiently by the opamp front-end of this amp in stock form.

Or maybe you improved current capability, which is a big determinant of PRaT, IME,

[opus101]

Just now, audiobomber said:

Or maybe you improved current delivery, which is a big determinant of PRaT, IME,

 

If by 'improved current delivery' you mean I lowered the PSU impedance then yes, I did. In another sense I restricted current delivery because I changed over from series regulation to shunt regulation. Shunt regulators tend to have a lower maximum current capability than series.

 

There does tend to be rather a mis-match in vocabulary between those with EE/tech backgrounds and those without. I am curious about finding ways to link up the two domains.

[audiobomber]

5 hours ago, hopkins said:

An anti-audiophile diatribe coming from an audiophile? Your non-sensical explanation that follows makes you sound more like a troll than anyone else. Transient response, attack sustain decay release are meaningless concepts in digital audio - these are just terms you  use to  express the impressions you get when a track is accurately reproduced and gives you a sense of PRaT.

 

In digital audio, things are very simple: either a recording is accurately reproduced by a DAC or it isn't. If it is, then everything else,  including PRaT, soundstage, ect.. follows. 

 

Arthur is not an audiophile, he is an anti-audiophile.

 

"Attack decay sustain release" is applicable to musical instruments and to music reproduction. A DAC needs to convert the digital signal to analog, then the analog stage needs to pass the signal on an amplifier. How well it handles these functions determines sound quality, and PRaT is a major determinant of SQ.

 

https://support.apple.com/en-ca/guide/logicpro/lgsife419620/mac

[audiobomber]

31 minutes ago, opus101 said:

 

If by 'improved current delivery' you mean I lowered the PSU impedance then yes, I did. In another sense I restricted current delivery because I changed over from series regulation to shunt regulation. Shunt regulators tend to have a lower maximum current capability than series.

 

There does tend to be rather a mis-match in vocabulary between those with EE/tech backgrounds and those without. I am curious about finding ways to link up the two domains.

Don't worry about vocabulary, I studied electrical and electronics theory in college. It was a long time ago, but I don't think the basics have changed. 

 

What I mean by current delivery is that the amp needs to provide the required amount of current to satisfy the load, in the proper amount, and on time. If it fails to do so, the result is current clipping, which can occur on transients even when current demand is well below maximum rated power. IMO, current delivery or current sourcing, is the main reason high-end amps sound better than mid-fi amps, even though both carry similar power ratings.

 

Audio Engineer's Reference Book 2.8.3 (2)

"The amplifier may run out of ability to provide the highest peak instantaneous output currents required, even though it may have something in hand for peak voltages. This is called current clipping."

 https://books.google.ca/books?id=XOvf30iChsYC&pg=SA2-PA118&lpg=SA2-PA118&dq=amplifier+"current+clipping"&source=bl&ots=DdxLBLbZWb&sig=ACfU3U3y7TE1ekpKonvy99i6-bsCr7EbBg&hl=en&sa=X&ved=2ahUKEwiJ993K3LTjAhVGOs0KHZCDCRcQ6AEwB3oECAkQAQ#v=onepage&q=amplifier "current clipping"&f=false

[opus101]

6 minutes ago, audiobomber said:

What I mean by current delivery is that the amp needs to provide the required amount of current to satisfy the load, in the proper amount, and on time. If it fails to do so, the result is current clipping, which can occur on transients even when current demand is well below maximum rated power. IMO, current delivery or current sourcing, is the reason high-end amps sound better than mid-fi amps.

 

 

I'd agree, the basics haven't changed. Here 'current delivery' only applies to the power stage of an amp where the load impedance (the speaker) isn't precisely known. In the case of my particular mods I didn't change anything in the power stage, rather I modified the power supplies to the signal stage. In signal stages the load impedance is known and opamps don't go into current limit ('current clipping') unless the designer's made a grave error.

 

What I suspect was happening in the stock amp was noise from the power stage supplies was 'bleeding through' to the signal stage supply, due to the regulators not being up to the job (insufficient line rejection). They also had too high an output impedance due to them feeding just a pair of opamps (about 8mA) - regulator output impedance is quite a strong function of output current and 8mA from a TO-220 reg is almost a negligible amount where the max rating is 1.5A.

[PeterSt]

2 hours ago, Archimago said:

 

What I'm interested in (and I suspect many "objective" types) is actually not whether any one person's listening experience is felt to be "good" or "bad". Subjective experience is simply the emergent property of that individual.

 

I don't see much how anyone, self-acclaimed objectivist, can be interested in what any two or 200 person's listening experiences are because you set your mind in advance to what can and what can not be. It is supported by well-documented etc. stuff, so why would you care.

I say: you don't care at all (this is not personal-addressed btw, but you could help working this out). So ...

 

So IMHO all you do is going against otherwise (for decades and beyond) very well recognized audiophile terms and experiences and indeed spoil the fun of those who are sure they hear the phenomenon in order. So indeed, why would you care ?

You don't. But, you try to improve the world ?

 

And so it now appears that we're not even allowed to talk about PRaT any more, BUT if one dares to challenge its existence it out of all turns into attack envelope sustain, decay and release. Sure.

This (again IMHO) all turns into one big mess and nothing is left from this hobby.

 

A kazillion attributes belong to amps, dacs, speakers and cables and even fuses. They all live in our subjective minds but may be real just the same. But if no-one is allowed to talk about such phenomena or else he gets burned, then there's nothing left to do out here but watching the few who seem to rule this world where all sounds the same.

Btw, there would also not be left anything to develop - just saying.

 

If someone has an opinion on how PRaT could be improved (like accurately following the transients - as a suggestion from someone), then other opinions are obviously the most welcome. Everybody may learn from it - me surely too. It could even be an interesting subject because it would be a most difficult one. The response(s) should not be in the magnitude of "show me measurements about that or else you have been smoking too much".

 

Something else would be that those who claim that PRaT only emerges during the recording - or even the playing by the artist, clearly don't even know what PRaT is or means. The fact that you never heard (of) it, means that you should stay out of the discussion and not that you like to see measurements of it, of which everybody knows that they won't exist in the first place.

 

So all you explicitly create is fight. Maybe that is the fun of 2021 (and really introduced by March Audio), but I don't think it is fun at all.

 

Sorry for the rant, but it greatly disturbs me, and I think I am not alone.

[PeterSt]

For a bit of balance:

 

2 hours ago, Archimago said:

When I have a "standard" DAC (these days typically my RME ADI-2 Pro FS R Black Edition) and a "comparison" DAC side-by-side, then maybe I can make some consistent comments - but even then it's within the context of the whole system, room, ambient noise level, listener experience / hearing acuity, etc.

 

100% agreed. But I think this is how it becomes important that more observations (preferably 100s) would lead to the same conclusion.

 

What would be wrong-ish is that you just declared the RME ADI-2 Pro FS as a reference.

Why ?

I own one. It is no reference for me. Oh, for measurement figures perhaps. And hey, did I see talk about the Topping D50 ? measures great but I too say it sucks the life out of all. And I think I have read many more of these observations.

 

It is not so easy. Talk about it as adults (with you as an example, if I may say so) would be great.

 

 

[Qhwoeprktiyns]

5 hours ago, March Audio said:

Im not sure where that leaves us if people wont believe measurements and subjective listening tests.

 

No one said this was going to be easy!

 

Measurements are interesting but may not capture everything, and there are millions of reasons why subjective impressions (starting with our own) can be challenged.

[Qhwoeprktiyns]

5 hours ago, Archimago said:

Don't forget that also whether a certain piece of music sounds good for the "listening experience" is actually the domain of the artist and production team.

 

Gee, thanks for the reminder.

[charlesphoto]

If you don't know Naim, you don't know PRaT!

 

(sorry couldn't resist)

[MaxBuck]

18 hours ago, hopkins said:

 

Perhaps. But now think back about CD players. We had no trouble accepting the fact that a high quality CD player sounded better than a cheap one.

Speak for yourself. I never heard any, regardless of how much salesmanship was at play.

[Archimago]

12 hours ago, PeterSt said:

I don't see much how anyone, self-acclaimed objectivist, can be interested in what any two or 200 person's listening experiences are because you set your mind in advance to what can and what can not be. It is supported by well-documented etc. stuff, so why would you care.

I say: you don't care at all (this is not personal-addressed btw, but you could help working this out). So ...

 

I don't think I've set my mind "in advance". The point is that subjective beliefs and experiences are too unreliable to draw many conclusions from. What "well documented" stuff are you talking about?

 

I do care, but not about everything that some people claim.

 

Quote

 

So IMHO all you do is going against otherwise (for decades and beyond) very well recognized audiophile terms and experiences and indeed spoil the fun of those who are sure they hear the phenomenon in order. So indeed, why would you care ?

You don't. But, you try to improve the world ?

 

Again, what "well recognized audiophile terms and experiences" are you referring to? There are plenty of claims over the decades that seem to be without merit. For example, .all kinds of people talk about "jitter" for decades now... As far as I can tell, it's not the objective folks who use this term often for sound quality yet the objective definition seems to be co-opted as if subjectively a significant property. Is this one of these "well recognized audiophile terms" you're referring to with "experience" and perhaps "fun" to talk about? But is it for real?

 

Quote

And so it now appears that we're not even allowed to talk about PRaT any more, BUT if one dares to challenge its existence it out of all turns into attack envelope sustain, decay and release. Sure.

This (again IMHO) all turns into one big mess and nothing is left from this hobby.

 

Feel free to talk about PRaT. I'm not stopping you even if I voice uncertainly about the meaning or usefulness of this. I don't know if you mean to sound this way, since clearly English is not your primary language, but the whole "attack envelope sustain..." bit sounds a bit dramatic??? 

 

Quote

A kazillion attributes belong to amps, dacs, speakers and cables and even fuses. They all live in our subjective minds but may be real just the same. But if no-one is allowed to talk about such phenomena or else he gets burned, then there's nothing left to do out here but watching the few who seem to rule this world where all sounds the same.

Btw, there would also not be left anything to develop - just saying.

 

Again, who's stopping you from talking about this? I'm just asking questions and stating that I don't see these things as concerns and voice my opinion that "fuses" and such things are likely Snake Oil. Just because some people in this world subjectively believe in something or other doesn't mean I'm here to literally stop individuals from such beliefs. Feel free to engage and demonstrate that some of these things (like fuses) make a difference in the audio chain...

 

I'm happy that audio can and should develop but also OK with the idea that maybe much of audio tech is also matured. In the big picture there are still places we can proceed in audio - multichannel, better Class-D, DSP tech, active speakers may be examples of things to do and develop even if area like standard 2-channel DACs, cables, traditional amps might already be excellent.

 

Quote

If someone has an opinion on how PRaT could be improved (like accurately following the transients - as a suggestion from someone), then other opinions are obviously the most welcome. Everybody may learn from it - me surely too. It could even be an interesting subject because it would be a most difficult one. The response(s) should not be in the magnitude of "show me measurements about that or else you have been smoking too much".

 

I agree, not everyone has measurements to show. Realize that I rarely intrude into other people's business. For example, I don't think you've seen me in your Lush^* thread, right?

 

However, on a "General Forum" like here, I see nothing wrong with stating an opinion when it comes to a general question like USB power and suggesting that people have some evidence for claims like "noise" before getting all excited about what may be a lot of nothing!

 

As for PRaT, I certainly welcome reasoned opinions and discussions as to how a person determined for him/herself whether something works to improve it or not. And what method is used to optimize this...

 

Quote

 

Something else would be that those who claim that PRaT only emerges during the recording - or even the playing by the artist, clearly don't even know what PRaT is or means. The fact that you never heard (of) it, means that you should stay out of the discussion and not that you like to see measurements of it, of which everybody knows that they won't exist in the first place.

 

?? When did I say I never "heard of it". Who is the "everybody" you speak of ??

 

Quote

So all you explicitly create is fight. Maybe that is the fun of 2021 (and really introduced by March Audio), but I don't think it is fun at all.

 

Sorry for the rant, but it greatly disturbs me, and I think I am not alone.

 

Likewise, this mindset you have is disturbing on many levels as well... And perhaps worse when I'm not sure I even understand what you mean a lot of the time.

[cab33]

15 hours ago, opus101 said:

 

There does tend to be rather a mis-match in vocabulary between those with EE/tech backgrounds and those without. I am curious about finding ways to link up the two domains.

 

 

cables

[Qhwoeprktiyns]

Here's another engineer (B.Putzeys) talking about the challenges of digital audio:

 

https://www.stereonet.com/forums/topic/317371-bruno-putzeys-darko-interview/

 

Here's a well respected DAC designer (among other things) who actually uses measurements to some extent (as most serious engineers do) - he's talked about how he uses them, but I cannot find that link. In his view, measurements were never meant to be used as a complete framework for evaluating equipment performance. 

 

I actually have not listened to the whole interview but trust the short summary provided in the link is accurate. 

[Archimago]

26 minutes ago, hopkins said:

Here's another engineer (B.Putzeys) talking about the challenges of digital audio:

 

https://www.stereonet.com/forums/topic/317371-bruno-putzeys-darko-interview/

 

Here's a well respected DAC designer (among other things) who actually uses measurements to some extent (as most serious engineers do) - he's talked about how he uses them, but I cannot find that link. In his view, measurements were never meant to be used as a complete framework for evaluating equipment performance. 

 

I actually have not listened to the whole interview but trust the short summary provided in the link is accurate. 

 

Yes, but also make sure to balance Putzey's comments with what he says elsewhere and how he approaches issues:

https://www.soundstagexperience.com/index.php/wesworld-menu/feature-articles-reviews-menu/720-bruno-putzeys-navigates-toward-the-state-of-the-art

 

https://www.audioholics.com/audio-amplifier/amp-myths-negative-feedback

 

Back in 2011 he also had a white paper talking about the "baroque prose" of high fidelity writings:

https://www.yumpu.com/en/document/read/28060563/ncore-technology-white-paper-hypex

 

Things are complicated. But let's keep it rational.

[audiobomber]

George Klissarov of exaSound:

 

“Power conditioning and noise-filtering works fine for traditional analogue audio devices. However, they are not sufficient to solve the issue of digital noise. Noise caused by digital switching circuits can travel via the ground connections. To block the propagation of digital noise it is necessary to eliminate the electrical connection between the digital and the analogue subsystems. We achieve this by using several types of isolation components – transformers, optoelectronic couplers, and digital Isolators. Compartmentalizing various subsystems with isolators keeps the external noise out and the internal noise in. Digital inputs are isolated from the internal blocks of the PlayPoint DM. The digital subsystem is isolated from the analogue circuits, left is isolated from right.”

 

“Each of these refinements makes a contribution to sound quality. Combined, their effect is significant. With vanishingly low noise and distortion, every music detail is presented against a very low noise background, highlighting the micro and macro dynamics.”

https://darko.audio/2019/01/exasound-playpoint-dm-review/

 

[kumakuma]

4 minutes ago, audiobomber said:

George Klissarov of exaSound:

 

“Power conditioning and noise-filtering works fine for traditional analogue audio devices. However, they are not sufficient to solve the issue of digital noise. Noise caused by digital switching circuits can travel via the ground connections. To block the propagation of digital noise it is necessary to eliminate the electrical connection between the digital and the analogue subsystems. We achieve this by using several types of isolation components – transformers, optoelectronic couplers, and digital Isolators. Compartmentalizing various subsystems with isolators keeps the external noise out and the internal noise in. Digital inputs are isolated from the internal blocks of the PlayPoint DM. The digital subsystem is isolated from the analogue circuits, left is isolated from right.”

 

“Each of these refinements makes a contribution to sound quality. Combined, their effect is significant. With vanishingly low noise and distortion, every music detail is presented against a very low noise background, highlighting the micro and macro dynamics.”

https://darko.audio/2019/01/exasound-playpoint-dm-review/

 

 

Someone trying to sell something... always a good objective source of information... 👺 

[audiobomber]

7 minutes ago, kumakuma said:

 

Someone trying to sell something... always a good objective source of information... 👺 

Yeah, I get it. The people who build this stuff don't know anything. We can't trust manufacturers or reviewers or other audiophiles, or our own ears. Just the measurements. 😆

[Qhwoeprktiyns]

24 minutes ago, Archimago said:

Things are complicated. But let's keep it rational

 

By simply claiming noise and jitter are none issues because:

 

"If there is a noise issue that can be addressed, I cannot imagine that they would not fix it. (To be clear, the DACs these guys I've spoken to make are not cheap!)" 

 

Give us a break! Where's the science there??? 

 

Your blog is a series of rants against audiophiles, and that's fine, but let's not take everyone for complete idiots please.