Is USB straight from a Mac computer to a DAC really that bad?

[audiophile911]

Is USB straight from a computer to a DAC really a bad or should everyone always strive to isolate the computer's USB output from the audio stream???  I connect my Chord Quest directly to my Mac Mini; which is dedicated to only running ROON Core; with an AudioQuest Diamond USB and I think it sounds great.  But I according to manufactures of network streamers, eliminating the computer (or using an expensive audio optimized PC like an Innuos) will always sound significantly better.  I've also read that this is not necessarily the case and it really depends on how usb is implemented in the source and the DAC?  Specifically, I heard from Rob Watts of Chord explain that Chord DAC's are optimized for USB direct input.  So, I'm trying to decide if I need to try something like a SOTM SMS-200 Ultra or a Sonore UltraRendu but I'm hesitant to go to the expense and hassle of more boxes.   I recently read this update on this $150K system: https://www.soundstagehifi.com/index.php/opinion/1392-after-25-years-is-this-the-worlds-best-audio-system  Specifically:

"Some Facebook readers criticized me for not using an audiophile-grade music server or USB link. I responded that if anyone can show me a music server or USB link that actually sounds better that what I have in terms of resolution, tonality, soundstaging, imaging, whatever -- I’m all ears. But so far, I’ve heard nothing that has proven itself better-sounding or more versatile -- my computer plays any digital music format and file type from streaming services and my local music drive, and my USB link, with its lengthy length, transfers the bits just fine.

The reason I can get away with using a laptop has to do with the next component in the signal chain: the EMM Labs DA2 Reference DAC ($25,000). Designed by Ed Meitner, who’s been creating digital-audio products since the 1970s, the DA2 Reference seems immune to swaps of USB links, as well as differences in source components."

 

Am I missing something??

[beerandmusic]

7 hours ago, davide256 said:

Actually they would be mystified as to why you are reducing  a layer 7 application level problem to just a  layer 2 link level problem... assuming they were educated  in computer technology and data transmission. Which is definitely not the skill set of a DAC engineer.

There is NO application problem in the transfer of bits where the bits are received with 100% accuracy. Everyone to date has agreed that the bits are received accurately.  And it also has been stated that if bits are dropped that it would be heard as a tic, not as "clarity" in music as you have suggested.

[sandyk]

41 minutes ago, beerandmusic said:

no, you have childishly clicked disagree with every post i make, without offering any reasoning, even on posts that i never made a statement that you can disagree with.  In one such post I said I am trying to understand the logic of something, and that is all i said in that post, and you clicked disagree with.  There was NOTHING in the post to disagree with, i was asking a question.  You were just being annoying on purpose.  Next time read what i write, and if you do not understand what I am asking, then either don't respond, or ask for clarification, but don't disagree with a "question" i make when it is posed as a question.  You were just trying to be annoying and you know it.   Instead of just squabbling with me, or following me around, just put me on ignore, and I will ignore you as well so we can both go on peacefully. 

 I gave you an indepth explanation in post #49   but you have shown that you simply aren't interested in  any explanations that are in disagreement with your own P.O.V.  I only click Disagree(e.g. #36) when I have a problem with the content of a post , which is often based on actual hands on experience in that area as an  experienced DIY person who has constructed several DACs and has also done indepth investigations in the USB Audio area , including this old thread.

https://www.computeraudiophile.com/forums/topic/13905-continuing-pursuit-of-power-supply-improvements-and-improved-dac-performance/

 Your 5  "Disagrees'' ) appeared in quick succession showing that you quickly went through all my recent posts in different threads specially , just as another member who has already been banned a couple of times already is presently doing.

[beerandmusic]

10 minutes ago, sandyk said:

 I gave you an indepth explanation in post #49   but you have shown that you simply aren't interested in  any explanations that are in disagreement with your own P.O.V.  I only click Disagree when I have a problem with the content of a post , which is normally based on hands on experience in that area as an  experienced DIY person who has constructed several DACs and hyas also

done indepth investigations in the USB area , including this old thread.

https://www.computeraudiophile.com/forums/topic/13905-continuing-pursuit-of-power-supply-improvements-and-improved-dac-performance/

 Your 5  "Disagrees'' ) appeared in quick succession showing that you quickly went through all my recent posts in different threads specially , just as another member who has already been banned a couple of times already is presently doing.

I didn't click disagree with you UNTIL AFTER you clicked disagree with a question i had.  It makes no sense to disagree with a question.  I have removed my "disagrees with you".  Please just put me on ignore.

 

[beerandmusic]

7 hours ago, davide256 said:

Actually they would be mystified as to why you are reducing  a layer 7 application level problem to just a  layer 2 link level problem... assuming they were educated  in computer technology and data transmission. Which is definitely not the skill set of a DAC engineer.

 

Or perhaps, let me ask it in a different way.  If you believe that the data is streamed differently than the bit-pefect flat file (lets just assume flac file pcm), how would you know that it is not transmitted without corruption, and what would it sound like, if a few bits were received incorrectly?

[beerandmusic]

8 hours ago, davide256 said:

Actually they would be mystified as to why you are reducing  a layer 7 application level problem to just a  layer 2 link level problem... assuming they were educated  in computer technology and data transmission. Which is definitely not the skill set of a DAC engineer.

 

Very informative regarding what I am speaking about:::

 

http://www.realhd-audio.com/?p=5971

 

esp...I can confidently state that you’ve never heard a timbral or fidelity change when connecting a digital source and a destination using a USB cable.  (with crc errors, you may get glitch, but unlikely, and you would hear it as a dropout, not as change in sq).

 

[audiobomber]

On 6/7/2020 at 6:27 AM, beerandmusic said:

http://www.realhd-audio.com/?p=5971esp...I can confidently state that you’ve never heard a timbral or fidelity change when connecting a digital source and a destination using a USB cable.  (with crc errors, you may get glitch, but unlikely, and you would hear it as a dropout, not as change in sq).

I disagree, and I believe so do most of the people on this website. I'm not sure why you are still here belaboring this point. If that's what you believe, just buy AnyDAC and be happy. 

 

This is an old article but the basic principles hold up today, IMO.

http://www.enjoythemusic.com/magazine/manufacture/0509/

[beerandmusic]

41 minutes ago, audiobomber said:

I disagree, and I believe so do most of the people on this website. I'm not sure why you are still here belaboring this point. If that's what you believe, just buy AnyDAC and be happy. 

 

This is an old article but the basic principles hold up today, IMO.

http://www.enjoythemusic.com/magazine/manufacture/0509/

 

I am not going to read the entire article, but if you want to share what are the line(s) that state what the resulting sound will be in the case of loss bits, i will entertain the thought?

 

This discussion came up many times, and i used to be on the other side of the thinking...but it seemed all/most of the audio engineers here agreed that the bits are received correctly and when not, it just caused a glitch.

 

 

 

 

 

[davide256]

21 minutes ago, beerandmusic said:

 

I am not going to read the entire article, but if you want to share what are the line(s) that state what the resulting sound will be in the case of loss bits, i will entertain the thought?

 

This discussion came up many times, and i used to be on the other side of the thinking...but it seemed all/most of the audio engineers here agreed that the bits are received correctly and when not, it just caused a glitch.

 

 

 

 

 

you need to stop spouting BS. What you mean is the engineers you want to agree with in the objective camp are spouting this... not the engineers who are actually exploring and selling products that aren't limited to midfi level of fidelity

[beerandmusic]

4 minutes ago, davide256 said:

you need to stop spouting BS. What you mean is the engineers you want to agree with in the objective camp are spouting this... not the engineers who are actually exploring and selling

products.

 

I don't want to agree with one side of the camp or the other.  I am unbiased, and just want the facts.

Two years ago, i started this a topic with this same thinking...

============================================================

As a matter of fact, here is an exact quote of mine from 2 years ago:::

 

I accept noise of all types affect SQ, but everyone kept suggesting that the DAC gets the music bits perfectly, but that noise affects the dac in processing.  This suggests that the DAC doesn't even receive the music bits with accuracy due to noise....big difference.  Some suggest that dacs can resolve for most noise, that's all dandy, but if the music is already inaccurate before it gets to the DAC input pin(s), there is no way to fix it at that point, if it is already corrupted.

===========================================================

The topic ended with basically no one agreeing with me or IFI....that bits lost are either SO RARE and even if they do happen it would cause a dropout, not a difference in SQ....but if people think differently today, that certainly goes along more with what I find logical.

 

[beerandmusic]

^^^  I will bring the old topic back to life and see if there is still a consensus....

IMHO, the only thing that is logical to me is that noise does indeed cause corruption of data and therefore distortion as far as why a LPS on a unix fanless computer would sound better than a general purpose windows machine?

 

Again, i am not on either side of "any camp"...i just want to understand the logic and reasoning.

 

From 2 years ago, I thought most everyone agreed the bits were "nearly" always perfect and if they weren't you would hear dropouts. 

[beerandmusic]

I also used to believe that higher sampling rate meant more resolution, but what i read recently is that you don't hear more music because of more sampling times, it's just that upsampling pushes distortion (due to dac's reconstruction filters) above the audible spectrum....but that you don't need dsd rates to do that.  Most all recordings are at 44.1K and that covers the entire audible spectrum.

 

Given:

a) 44.1K covers our audible hearing

b) most recordings are at 44.1K or 48K

 

My current understanding is that 96K should be more than sufficient, and why would we want to upsample higher and even mess with DSD which introduces more problems.

 

No blind test to date has supported that DSD sounds better than high rate pcm.

 

Until I have just recently revisited my thoughts (clearly not an audio engineer), but I am actually thinking PCM may be better than DSD now.

[beerandmusic]

35 minutes ago, beerandmusic said:

 

I don't want to agree with one side of the camp or the other.  I am unbiased, and just want the facts.

Two years ago, i started this a topic with this same thinking...

============================================================

As a matter of fact, here is an exact quote of mine from 2 years ago:::

 

I accept noise of all types affect SQ, but everyone kept suggesting that the DAC gets the music bits perfectly, but that noise affects the dac in processing.  This suggests that the DAC doesn't even receive the music bits with accuracy due to noise....big difference.  Some suggest that dacs can resolve for most noise, that's all dandy, but if the music is already inaccurate before it gets to the DAC input pin(s), there is no way to fix it at that point, if it is already corrupted.

===========================================================

The topic ended with basically no one agreeing with me or IFI....that bits lost are either SO RARE and even if they do happen it would cause a dropout, not a difference in SQ....but if people think differently today, that certainly goes along more with what I find logical.

 

To clarify I was quoting articles by IFI and Gordon Rankin, and everybody (at least everybody that spoke up), found exception to my statement that audio transmission is not bit perfect....so i accepted the consensus...and now it appears that there are people that may actually believe what I was trying to say 2 years ago....well we will see where it goes from here.

[audiobomber]

On 6/7/2020 at 6:27 AM, beerandmusic said:

 

Very informative regarding what I am speaking about:::

 

http://www.realhd-audio.com/?p=5971

 

esp...I can confidently state that you’ve never heard a timbral or fidelity change when connecting a digital source and a destination using a USB cable.  (with crc errors, you may get glitch, but unlikely, and you would hear it as a dropout, not as change in sq).

 

I agree that lost bits will cause a pop or dropout. Lost bits are not the reason that digital systems sound different. You really should take ten minutes to read the article I linked, it explains jitter and its various origins extremely well. For example:

6. Power subsystem
The DC power applied to each of the devices that must process or transmit the digital audio signal is critical. If this power varies in voltage, the devices will react differently to the applied digital signals. Power "noise" as it is referred to is probably one of the largest contributors to jitter. Voltage changes or "voltage droop" can happen anywhere on a circuit board, power cabling, or even on the silicon itself. Changes in power voltage will change the speed and reaction times of digital logic that is transmitting the digital signals resulting in jitter.

8. Digital Cables
Cables don't actively add jitter to the signal, however they can slow the signal transitions or "edges". When the edges are slowed, the receiver or buffer at the cable destination is less likely to detect the transition at the correct time with certainty, which results in jitter.

10. Printed circuit board effects
There are at least two effects on a circuit board that can cause jitter, including signal crosstalk and ground-bounce. Crosstalk occurs when traces with high-speed signals are spaced closely. One signal induces voltage on the other signal. It is obvious how this can add to jitter. Ground-bounce occurs when the signal return current see a high-impedance on the circuit board due to ground-plane splits or long return paths. This creates a voltage drop in the ground-plane or return path. This voltage drop causes the signal to shift in voltage, which can result in jitter.

http://www.enjoythemusic.com/magazine/manufacture/0509/

[beerandmusic]

19 minutes ago, audiobomber said:

I agree that lost bits will cause a pop or dropout. Lost bits are not the reason that digital systems sound different. You really should take ten minutes to read the article I linked, it explains jitter and its various origins extremely well. For example:

6. Power subsystem
The DC power applied to each of the devices that must process or transmit the digital audio signal is critical. If this power varies in voltage, the devices will react differently to the applied digital signals. Power "noise" as it is referred to is probably one of the largest contributors to jitter. Voltage changes or "voltage droop" can happen anywhere on a circuit board, power cabling, or even on the silicon itself. Changes in power voltage will change the speed and reaction times of digital logic that is transmitting the digital signals resulting in jitter.

8. Digital Cables
Cables don't actively add jitter to the signal, however they can slow the signal transitions or "edges". When the edges are slowed, the receiver or buffer at the cable destination is less likely to detect the transition at the correct time with certainty, which results in jitter.

10. Printed circuit board effects
There are at least two effects on a circuit board that can cause jitter, including signal crosstalk and ground-bounce. Crosstalk occurs when traces with high-speed signals are spaced closely. One signal induces voltage on the other signal. It is obvious how this can add to jitter. Ground-bounce occurs when the signal return current see a high-impedance on the circuit board due to ground-plane splits or long return paths. This creates a voltage drop in the ground-plane or return path. This voltage drop causes the signal to shift in voltage, which can result in jitter.

http://www.enjoythemusic.com/magazine/manufacture/0509/

 

none of that speaks to what the actual sound difference is, that jitter by noise causes...i vaguely remember (but i may be wrong), that someone (archimago maybe?) that shared what "jitter" sounds like, and if i recall it was like hiss.  If i hear ticks or hiss, then i would be concerned, but I do not.   my point is that i believe that "modern day dacs" should compensate for any noise on usb line, and my current belief is that they do.  Provided they have what "unsion" has or better which includes, use their own 5v reference, isolating the usb's 5v reference, galvanic isolation, and reclocking.  I am sure there are other modern day dacs that do this as well, and some are now using LPS's as well.

[The Computer Audiophile]

2 minutes ago, beerandmusic said:

 

none of that speaks to what the actual sound difference is...i vaguely remember (but i may be wrong), that someone (archimago maybe?) that shared what "jitter" sounds like, and if i recall it was like hiss.  If i hear ticks or hiss, then i would be concerned, but I do not.   my point is that i believe that "modern day dacs" should compensate for any noise on usb line, and my current belief is that they do.  Provided they have what "unsion" has or better which includes, use their own 5v reference, isolating the usb's 5v reference, galvanic isolation, and reclocking.  I am sure there are other modern day dacs that do this as well, and some are now using LPS's as well.

In my experience jitter can round the edges of transients and make music sound soft. 

[audiobomber]

1 minute ago, The Computer Audiophile said:

In my experience jitter can round the edges of transients and make music sound soft. 

Agree, and/or cause sibilance.

[6aardvark9]

1 minute ago, The Computer Audiophile said:

In my experience jitter can round the edges of transients and make music sound soft. 

 

Quite the opposite for me... I consider jitter to cause digital glare and top end harshness

[davide256]

9 hours ago, beerandmusic said:

 

I don't want to agree with one side of the camp or the other.  I am unbiased, and just want the facts.

Two years ago, i started this a topic with this same thinking...

============================================================

As a matter of fact, here is an exact quote of mine from 2 years ago:::

 

I accept noise of all types affect SQ, but everyone kept suggesting that the DAC gets the music bits perfectly, but that noise affects the dac in processing.  This suggests that the DAC doesn't even receive the music bits with accuracy due to noise....big difference.  Some suggest that dacs can resolve for most noise, that's all dandy, but if the music is already inaccurate before it gets to the DAC input pin(s), there is no way to fix it at that point, if it is already corrupted.

===========================================================

The topic ended with basically no one agreeing with me or IFI....that bits lost are either SO RARE and even if they do happen it would cause a dropout, not a difference in SQ....but if people think differently today, that certainly goes along more with what I find logical.

 

If you want not to be years behind in where computer audio has gone, you need to devote a weekend to reading the thread below. A lot of research by many different CA members with converging results and some key findings linked/ summarized up front. I ignored it in 2017-18 only to find out I had spent time and money duplicating results/conclusions already reached

in the thread and needed to catch up.

 

 

[audiobomber]

1 minute ago, 6aardvark9 said:

 

Quite the opposite for me... I consider jitter to cause digital glare and top end harshness

IME, it can do either.

[beerandmusic]

12 minutes ago, The Computer Audiophile said:

In my experience jitter can round the edges of transients and make music sound soft. 

 

Ok, if i accept that, even though i believe i saw a posting at one time that actually recorded jitter inserted into a signal and it sounded like hiss, but i suppose different kinds of jitter can cause different things.

 

Let's assume it causes distortion in the audible range that actually makes music lose detail.  (I have heard loss of detail and actually have a test track that i do critical listening for it, and have heard different degrees of loss detail).

 

But it is still my contention that a well designed dac should compensate for this....and to be honest, i do believe the unison does this quite well.  They market that it provides it's own 5v reference, that it is galvanically isolated the usb, and that it reclocks.

I now can hear out my general use pc the same music of my test track that before i only heard from dsd over dlna or by playing same track in a usb slot.  (granted i have never tried usb toys before or specialized music pcs).

 

I have been griping since several years back ago, that DACs should be designed to compensate for any noise on the usb bus, I think the unison finally does that.  There may be other dacs that do it as well, but of the 15 or so i have tried, i have always fared better with dsd via dlna or using a thumbdrive, and that was 7-8 years ago now....back then i would just do dsd via dlna using a used $80 sony bluray player....i never got caught up in the usb toy thing or the more recent sotm or sonore enet products.  The unison interface playing just plain pcm is very close if not equal to the dsd via dlna i have experienced...and DLNA has it's own issues...so i am finally content with usb.

 

[davide256]

4 minutes ago, The Computer Audiophile said:

In my experience jitter can round the edges of transients and make music sound soft. 

hmm, that sounds much like what more modest tube gear does. Which some actually like... probably a necessity if you still have use Koss 1 electrostatic speakers

 

7 minutes ago, 6aardvark9 said:

 

Quite the opposite for me... I consider jitter to cause digital glare and top end harshness

tended to find this linked more to source hardware and power supply quality. Of course a PS Audio Dlink III could make any source sound like that

 

what I've experienced is that timing degradation in the source causes background instruments to lose definition

[audiobomber]

5 minutes ago, beerandmusic said:

But it is still my contention that a well designed dac should compensate for this....and to be honest, i do believe the unison does this quite well.  They market that it provides it's own 5v reference, that it is galvanically isolated the usb, and that it reclocks.

 

I have been griping since several years back ago, that DACs should be designed to compensate for any noise on the usb bus, I think the unison finally does that. 

If you think that the Unison is the answer to perfect USB playback, you should get the $199 Modius.

 

Of course I am being facetious, there's a lot more to a DAC than the USB implementation.

[The Computer Audiophile]

13 minutes ago, davide256 said:

If you want not to be years behind in where computer audio has gone, you need to devote a weekend to reading the thread below. A lot of research by many different CA members with converging results and some key findings linked/ summarized up front. I ignored it in 2017-18 only to find out I had spent time and money duplicating results/conclusions already reached

in the thread and needed to catch up.

 

 

 

While a very cool thread and very cool findings contained within, I would never characterize it with the sentence, "If you want not to be years behind in where computer audio has gone." There are many paths to Rome. I enjoy many of them equally.

[audiobomber]

2 minutes ago, davide256 said:

what I've experienced is that timing degradation in the source causes background instruments to lose definition

The main timing degradation for me is poor PRaT. I had a CD transport and DAC with separate clock link. Disconnecting the clock link caused no difference in tonality, but the music became boring. Instead of being riveted to the music, my attention wandered. No boogie factor, or in Linn terms, no foot-tapping.

[beerandmusic]

9 minutes ago, davide256 said:

If you want not to be years behind in where computer audio has gone, you need to devote a weekend to reading the thread below. A lot of research by many different CA members with converging results and some key findings linked/ summarized up front. I ignored it in 2017-18 only to find out I had spent time and money duplicating results/conclusions already reached

in the thread and needed to catch up.

 

 

 

there is more than one way to skin a cat, and that thread is NOT for me (not knocking it, i am just not an audio DIY'er).

 

I was streaming DSD via DLNA via a cheapo SONY bluray player long before that thread or popularity of usb toys or music via enet existed...and I swore by it, when everyone else told me i was crazy.

 

I believe that modern day dacs have worked on usb deficiencies while everyone in that thread has found other solutions to the usb problems.

 

I believe a noisy usb can cause problems down the chain, but i don't believe it can corrupt the digital data before it is recieved by the dac (and even if it did, it would cause noticable dropouts).  Perhaps the noisy 5v or even the noise on the bits can wreak havoc on older dacs...but that a well designed dac should be able to compensate for this noise, and I believe the unison finally does that, and i am sure there are other dacs that do as well....technology does advance, and there is always more than one way to skin a cat.