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??

[audiobomber]

1 hour ago, beerandmusic said:

 

Do you agree that the only thing that is sent from the usb to the dac is:

a) digital music (most everyone agrees that this digital data is received accurately)

b) reference voltage

c) noise

Noise and distortion with any current DAC is going to be below the level of real-world audibility. That's why ASR's SINAD measurements are worse than useless (i.e. misleading) for judging sound quality.

 

Timing is more important than noise, which is where current USB beats SPDIF, and also why USB treatments with reclocking, improved power supply, etc, usually improve the sound. But not all systems benefit from something between the transport and DAC. It depends on the DAC, digital transport and USB treatment.

 

PS You seem very high on the Schiit Unison. IMO it's more likely that their past USB implementation was substandard, and has only now caught up. I don't know any of the technical details, I'm only looking at their previous statements, that SPDIF sounded better than USB. That is never how it should be with a proper USB implementation.

[sandyk]

4 hours ago, beerandmusic said:

Also keep in mind liking the sound better does not always equate to accuracy and there may be some emotion and perception involved as well. 

Are you suggesting that one or both of the quoted devices above has forwarded corrupted Data to the receiver in the DAC ?

 If not, according to you, both should sound identical !

[Audiophile Neuroscience]

 

5 hours ago, beerandmusic said:

6 hours ago, AudioDoctor said:

Interestingly, my new DAC has a Roon Bridge built in, however I find the sound to be better coming from the USB output of a Sonore Signature Rendu SE via Roon and HQPlayer than using the Roon Bridge directly.

 

Also keep in mind liking the sound better does not always equate to accuracy and there may be some emotion and perception involved as well. 

 

Well, in either approach, one would truly hope emotion is involved ie evoked.

Perception must be involved otherwise you wouldn't hear it 🤔

If instead you were meaning expectation bias, that can work both ways.

If instead you were meaning effect of distortion products sounding more euphonic then I think that would need some evidence.

[davide256]

6 hours ago, beerandmusic said:

 

Do you agree that the only thing that is sent from the usb to the dac is:

a) digital music (most everyone agrees that this digital data is received accurately)

b) reference voltage

c) noise

Do you agree that the fuel pump on your car sends gas? And if so do you disagree that a fuel pump doesn’t behave any differently whether the gas is good or poor? That’s all asynch USB is, a “fuel pump” for the DAC that doesn’t care or know how good or bad it’s source is

[The Computer Audiophile]

7 hours ago, AudioDoctor said:

Interestingly, my new DAC has a Roon Bridge built in, however I find the sound to be better coming from the USB output of a Sonore Signature Rendu SE via Roon and HQPlayer than using the Roon Bridge directly.

If found this to be true in several cases. 

[davide256]

22 hours ago, AudioDoctor said:

Interestingly, my new DAC has a Roon Bridge built in, however I find the sound to be better coming from the USB output of a Sonore Signature Rendu SE via Roon and HQPlayer than using the Roon Bridge directly.

Yup, wrong direction to bring a specific software vendor's player implementation inside the DAC. A real ethernet DAC implementation should look very little different than a wired DAC

beyond having an IP address and a device driver based on IP, similar to attaching a remote printer and available to any program able to use the sound  device driver.

[beerandmusic]

nvm

[beerandmusic]

16 hours ago, davide256 said:

Do you agree that the fuel pump on your car sends gas? And if so do you disagree that a fuel pump doesn’t behave any differently whether the gas is good or poor? That’s all asynch USB is, a “fuel pump” for the DAC that doesn’t care or know how good or bad it’s source is

comparing good or bad gas would be more like comparing one song to another, and besides doesn't make sense to compare usb to a fuel pump.  usb always transmits the bits accurately, even if there is noise on the line....if you can get the bits perfectly, a good design should be able to compensate for any noise.

[6aardvark9]

Just now, beerandmusic said:

comparing good or bad gas would be more like comparing one song to another, and besides doesn't make sense to compare usb to a fuel pump.  usb always transmits the bits accurately.

 

It's the timing of delivery, not the fact that the right 'bits' get delivered. Accuracy has to apply to both, that's why master clocks make a difference and why high end dacs/streamers have external word clock inputs

[beerandmusic]

4 minutes ago, 6aardvark9 said:

 

It's the timing of delivery, not the fact that the right 'bits' get delivered. Accuracy has to apply to both, that's why master clocks make a difference and why high end dacs/streamers have external word clock inputs

 

I would not argue that...but that could/should be a function of the dac.

If the dac can get the bits accurately, the design of the dac should be able to take that "perfection" up to the conversion circuitry...especially when you have a dac that does it's "own" regneration...

 

this should not be rocket science...and perhaps we are already there, but just subjective opinions are creating their own market.

[6aardvark9]

1 minute ago, beerandmusic said:

 

I would not argue that...but that could/should be a function of the dac.

If the dac can get the bits accurately, the design of the dac should be able to take that "perfection" up to the conversion circuitry...especially when you have a dac that does it's own regneration...

 

I think in some respect its a limitation of the processing power... this is why Chord developed the MScaler to take a huge chunk of the upscaling outboard from the DAC, so that the DAC (Dave/Hugo(TT)2/Qutest) has less to do, thereby improving the 'sound'. They couldn't put both MScaler and Dave together in one box because of the required current draw (the BluMk2 CD transport draws up to 10A for MScaling, and gets f'ing hot to the touch.

[beerandmusic]

Just now, 6aardvark9 said:

 

I think in some respect its a limitation of the processing power... this is why Chord developed the MScaler to take a huge chunk of the upscaling outboard from the DAC, so that the DAC (Dave/Hugo(TT)2/Qutest) has less to do, thereby improving the 'sound'. They couldn't put both MScaler and Dave together in one box because of the required current draw (the BluMk2 CD transport draws up to 10A for MScaling, and gets f'ing hot to the touch.

 

this processing power is for "upsampling", which is a totally different subject, which i have my own debate about different than this one.

 

[6aardvark9]

1 minute ago, beerandmusic said:

 

this processing power is for "upsampling", which is a totally different subject, which i have my own debate about different than this one.

 

 

I would also add that the performance of Dave/MScaler is very much improved with upstream reclocking… 

[beerandmusic]

Just now, 6aardvark9 said:

 

I would also add that the performance of Dave/MScaler is very much improved with upstream reclocking… 

again, might not argue that point, but that is different topic.

 

 

[6aardvark9]

Just now, beerandmusic said:

again, might not argue that point, but that is different topic.

 

 

 

I thought it relevant, since the (reclocked/improved) timing of the digital signal makes a difference, even with high(er) end DACs

[beerandmusic]

5 minutes ago, 6aardvark9 said:

 

I thought it relevant, since the (reclocked/improved) timing of the digital signal makes a difference, even with high(er) end DACs

 

iimproved timing is likely needed for upsampled DSD rates which is not at least what i am looking for.

 

I just want to know if a technology such as unsion that includes isolation and regeneration is sufficient without getting into the debate of high-res which i consider a totally different topic, that i have my own and separate debate about.

[davide256]

3 hours ago, beerandmusic said:

comparing good or bad gas would be more like comparing one song to another, and besides doesn't make sense to compare usb to a fuel pump.  usb always transmits the bits accurately, even if there is noise on the line....if you can get the bits perfectly, a good design should be able to compensate for any noise.

So basically you are arguing that their is no difference between the output presented to USB from the cheapest computer possible to the best possible. Good luck with that approach,

you won't get past the level of sound quality you hear at a Walmart. Software, hardware and power supply do matter.

[davide256]

4 hours ago, beerandmusic said:

 

iimproved timing is likely needed for upsampled DSD rates which is not at least what i am looking for.

 

I just want to know if a technology such as unsion that includes isolation and regeneration is sufficient without getting into the debate of high-res which i consider a totally different topic, that i have my own and separate debate about.

Mehh, Unison is just an incremental improvement over Gen 5. I'm moving on.

[beerandmusic]

1 hour ago, davide256 said:

So basically you are arguing that their is no difference between the output presented to USB from the cheapest computer possible to the best possible. Good luck with that approach,

you won't get past the level of sound quality you hear at a Walmart. Software, hardware and power supply do matter.

 

No, I am not arguing there is no difference, I am questioning the logic and reasoning.  You would think a DAC engineer would be able to provide a "logical" explanation...but even DAC engineers shrug like they do not know why.

 

Keeping in sight these basic principles.

 

The only thing transferred to the dac from the pc are:

1. Digital bits (which everyone agrees the DAC receives with 100% accuracy)

2. A reference voltage

3. Noise

 

4. If you take into consideration that the DAC receives its bits with 100% accuracy and that the PC's reference voltage should have no impact since it is isolated from the DAC's Design.

 

5. If you take into consideration that the DAC has it's own reclocking/regeneration of the bits that it recieves with 100% accuracy, then the PC should not make any difference.

 

A different dac may make a difference, but a different pc should not make a difference if you accept 1-5.  If you don't accept 1-5, then which don't you accept and why?

 

Again, not comparing DAC A to DAC B, comparing using different pc's with same DAC.

 

[davide256]

5 hours ago, 6aardvark9 said:

 

I thought it relevant, since the (reclocked/improved) timing of the digital signal makes a difference, even with high(er) end DACs

Mojo's not exactly a higher end DAC but ratcheting up the source data rate to max PCM or DSD rates sure improves clarity of CD quality recordings.

[davide256]

1 minute ago, beerandmusic said:

 

No, I am not arguing there is no difference, I am questioning the logic and reasoning.  You would think a DAC engineer would be able to provide a "logical" explanation...but even DAC engineers shrug like they do not know why.

 

Keeping in sight these basic principles.

 

The only thing transferred to the dac from the pc are:

1. Digital bits (which everyone agrees the DAC receives with 100% accuracy)

2. A reference voltage

3. Noise

 

4. If you take into consideration that the DAC receives its bits with 100% accuracy and that the PC's reference voltage should have no impact since it is isolated from the DAC's Design.

 

5. If you take into consideration that the DAC has it's own reclocking/regeneration of the bits that it recieves with 100% accuracy, then the PC should not make any difference.

 

A different dac may make a difference, but a different pc should not make a difference if you accept 1-5.  If you don't accept 1-5, then which don't you accept and why?

 

Again, not comparing DAC A to DAC B, comparing using different pc's with same DAC.

 

DAC engineers would consider anything before the USB output as "someone else's black box"... they don't get paid to solve someone else's problems.

A software engineer for a computer audio program might be a better place to start... they could give you a sampling of technology reasons why current computer audio

is not "the best of all possible worlds"

[beerandmusic]

2 minutes ago, davide256 said:

 

DAC engineers would consider anything before the USB output as "someone else's black box"... they don't get paid to solve someone else's problems.

A software engineer for a computer audio program might be a better place to start... they could give you a sampling of technology reasons why current computer audio

is not "the best of all possible worlds"

 

Any software engineer (or hardware engineer) would state what I have...that the bits are transferred perfectly along with a reference voltage and noise.  I am not referencing potential issues with upsampling. 

[sandyk]

45 minutes ago, beerandmusic said:

 

Any software engineer (or hardware engineer) would state what I have...that the bits are transferred perfectly along with a reference voltage and noise.  I am not referencing potential issues with upsampling. 

 

The Data is sent as analogue waveforms , the shape of the waveforms and voltage levels, as well as the timing is dictated by the front end, and will also obviously look different at the DAC end of the cable which in the case of USB may be <1M long,  or not much more than 5 Metres long,(at which length errors may occur) where the input circuitry (Schmidt Trigger etc.) will try to convert it into a correct

1 or 0.
With a less than perfect input waveform, the receiver's Schmidt Trigger etc may toggle at a slightly different part of the waveform, resulting in some timing variations.

This also applies to Coax SPDIF where they may use a Schmidt trigger (e.g. 74HCU04)

 to try and " square up" the waveform.

 

 I get it that you don't like what I am saying, so now feel the need to childishly revisit every recent post I have made as payback, on any subject ,and click Disagree, like in the case of the recently banned Charleslatham who  felt the need to click " laugh" on every post by 2 members.

 

See for example

#528

[davide256]

1 hour ago, beerandmusic said:

 

Any software engineer (or hardware engineer) would state what I have...that the bits are transferred perfectly along with a reference voltage and noise.  I am not referencing potential issues with upsampling. 

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.

[beerandmusic]

7 hours ago, sandyk said:

 

The Data is sent as analogue waveforms , the shape of the waveforms and voltage levels, as well as the timing is dictated by the front end, and will also obviously look different at the DAC end of the cable which in the case of USB may be <1M long,  or not much more than 5 Metres long,(at which length errors may occur) where the input circuitry (Schmidt Trigger etc.) will try to convert it into a correct

1 or 0.
With a less than perfect input waveform, the receiver's Schmidt Trigger etc may toggle at a slightly different part of the waveform, resulting in some timing variations.

This also applies to Coax SPDIF where they may use a Schmidt trigger (e.g. 74HCU04)

 to try and " square up" the waveform.

 

 I get it that you don't like what I am saying, so now feel the need to childishly revisit every recent post I have made as payback, on any subject ,and click Disagree, like in the case of the recently banned Charleslatham who  felt the need to click " laugh" on every post by 2 members.

 

See for example

#528

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.