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]

10 minutes ago, Miska said:

 

Because the difference frequencies (intermodulation) between those fall into audio band.

 

 

You lost me....can we back up to this statement::  First image of DAC operating at 192 kHz from 44.1k source is around 192 kHz and spans form 169.95 kHz to 214.05, same repeats around 384 kHz, etc.

 

I believe you inferred that that is the measurable audible differences comparing a schiit mb dac output  of a 44.1K source as compared to an RME ADI-2 dac playing the same file upsampled to quad dsd.

 

What is this "difference" you are talking about that falls in the 20hz-50khz audio band?

 

[Miska]

6 minutes ago, beerandmusic said:

I believe you inferred that that is the measurable audible differences comparing a schiit mb dac output  of a 44.1K source as compared to an RME ADI-2 dac playing the same file upsampled to quad dsd.

 

Whatta heck is measurable audible? I said measurable. What is audible depends on many factors, including associated equipment.

 

6 minutes ago, beerandmusic said:

What is this "difference" you are talking about that falls in the 20hz-50khz audio band?

 

Digital filter response, analog filter response (phase and magnitude), analog stage harmonic and intermodulation behavior.

 

Remember that for example 1 kHz tone played has 2 kHz difference frequency from every image pair at multiples of 192 kHz. Now for your exercise, figure out how to distinguish contribution of such to the overall THD figure.

 

You will have especially fun time with class-D amplifiers that tend to exhibit aliasing effects on such high frequency inputs (Hypex etc).

 

[Miska]

In general, I rather have a conversion system that produces accurate results. Instead of trying to convince myself that I shouldn't hear all the inaccuracies.

 

[beerandmusic]

15 minutes ago, Miska said:

 

Whatta heck is measurable audible? I said measurable. What is audible depends on many factors, including associated equipment.

 

I said assuming hardware is the same.

I said what is measurable on the output that could make one sound better than the other.

Ideally you would have a perfect analog signal as represented by the original wav file.

 

hmmm...don't think i understand enough to ask the right questions.  I will give it a rest, and try to gather my thoughts.  I thought before talking to you that I had a logical concept in my mind that a 44.1k wav file would sound similar, whether it was output from a schiit mb dac or if it was output from a dsd dac where it was upsampled to quad dsd, but apparently not (grin).

 

[Miska]

6 minutes ago, beerandmusic said:

I said assuming hardware is the same.

 

Yes, same amplifier. But which amplifier?

 

Let's say we have DAC A and DAC B. DAC A is not perfect while DAC B is perfect. And we have amplifier Y and amplifier Z.

 

Amplifier Y likely behaves differently with DAC A, than amplifier Z. While both behave the same with DAC B (although they have their own fingerprint still, but just not changing due to the source).

 

[beerandmusic]

11 minutes ago, Miska said:

In general, I rather have a conversion system that produces accurate results. Instead of trying to convince myself that I shouldn't hear all the inaccuracies.

 

Now that makes sense to me....I am more about accuracy then even the sound (grin)....if it is accurate, but sounds like crap, I am ok with that...as long as it is accurate...seriously.  So if the bottom line is that if all the hardware is the same, that you will have a more accurate depiction of the wav file by upsampling everything to quad dsd than if you were to just upsample to 192k.

 

I actually believed until that statement that the analog signal would be the same due to wave shaping, and just assumed since more modifications were done on the higher resolution, that it would likely have more "noise" that needed to be corrected prior to wave shaping.

[beerandmusic]

2 minutes ago, Miska said:

 

Yes, same amplifier. But which amplifier?

 

Let's say we have DAC A and DAC B. DAC A is not perfect while DAC B is perfect. And we have amplifier Y and amplifier Z.

 

Amplifier Y likely behaves differently with DAC A, than amplifier Z. While both behave the same with DAC B.

 

 

If you have the "same" analog output from both dacs and the amplifier is the same the resulting sound should be the same...which is why i am asking for the measurable difference on the output that is within the audible range.

[sandyk]

43 minutes ago, Miska said:

That is sort of irrelevant for the topic here though.

Agreed

 Neither do I wish to get into discussions about the need for the substantial additional expense of converting everything to DSD which most consumers do not need, or the general public even know about.  How many members even have speakers that can do justice to much more than 20kHz, let alone worry about phase shifts at 50kHz or get the best from DSD  especially when using Hypex amplifiers as you mentioned.?

At the moment, it has been shown by John Dyson that it may be more rewarding to clean up the damage done with poor mastering techniques at 16/44.1 which can often sound like high res. when properly mastered without a lot of editing/mixing .

 Perhaps we need more " direct to disc "  type material using today's vastly improved electronics ?

 

[beerandmusic]

12 minutes ago, Miska said:

 

 

If you have the "same" analog output from both dacs and the amplifier is the same the resulting sound should be the same...which is why i am asking for the measurable difference on the output that is within the audible range.

-----

Perhaps i could gain better understanding if we started even with something simpler than a wav file.

 

How about if we start with just a 1khz sine wave, and we recorded it at 44.1khz

 

I would "think" that whether we upsampled it to 192K PCM or 256DSD that the output in both cases would be a perfect 1khz sine wave presented to our speakers.

[Miska]

Just now, beerandmusic said:

If you have the "same" analog output from both dacs and the amplifier is the same the resulting sound should be the same...which is why i am asking for the measurable difference on the output that is within the audible range.

 

Point is that the analog output from both DACs is not the same, it is massively different. Sure, you can make ADI-2 behave somewhat similarly by setting it into NOS mode and running it at 192k PCM. Instead of running it at 768k PCM or DSD256.

 

[Miska]

6 minutes ago, sandyk said:

 Neither do I wish to get into discussions about the need for the substantial additional expense of converting everything to DSD which most consumers do not need, or the general public even know about.  How many members even have speakers that can do justice to much more than 20kHz, let alone worry about phase shifts at 50kHz or get the best from DSD ?

At the moment, it has been shown by John Dyson that it may be more rewarding to clean up the damage done with poor mastering techniques at 16/44.1 which can often sound like high res. when properly mastered without a lot of editing/mixing .

 Perhaps we need more " direct to disc "  type material using today's vastly improved electronics ?

 

You are drifting vastly off-topic. But just curious, what additional expense?

 

What kind of DAC do you have? Because SDM (DSD) converters have way more than 95% market coverage in audio ADC and DAC. Also your mobile phone's microphone is a "native DSD microphone", although very few even know about it.

 

I'm fine discussing this for just RedBook content as well, my main concern are techniques to produce most accurate analog waveform from the DAC output regardless of the source content type.

 

[beerandmusic]

8 minutes ago, Miska said:

 

Point is that the analog output from both DACs is not the same, it is massively different. Sure, you can make ADI-2 behave somewhat similarly by setting it into NOS mode and running it at 192k PCM. Instead of running it at 768k PCM or DSD256.

 

Ok, i didn't realize that.

I thought the purpose of the dac is to present an accurate analog wave form which is a depiction of the bits in the source file...i thought they would/should be very close to identical on the analog output?

 

If they are vastly different, then we have a serious problem.

 

would they be vastly different even if the recording was just a one second 1khz sine wave?

 

 

[Miska]

1 minute ago, beerandmusic said:

Ok, i didn't realize that.

I thought the purpose of the dac is to present an accurate analog wave form which is a depiction of the bits in the wav file...i thought they would/should be very close to identical on the output to the speakers?

 

They are far from identical, and in modern systems involved DSP algorithms have huge contribution to the end result. As well as the conversion architecture and analog stages.

 

[audiophile911]

It's been interesting following my thread but except for a couple of posts most have not addressed the fundamental question from my original post.  Is it a bad idea to connect a mac mini directly to my DAC via usb?  I think it sounds good or am I missing something??

[beerandmusic]

11 minutes ago, audiophile911 said:

It's been interesting following my thread but except for a couple of posts most have not addressed the fundamental question from my original post.  Is it a bad idea to connect a mac mini directly to my DAC via usb?  I think it sounds good or am I missing something??

you haven't figured it out? 

 

The answer is always the same...."it depends"

"bad" is a relative word. 

 

The crowd isn't as rough as it use to be.

THe question really depends on if you are or will be an audiophile or not....you can always improve on it.  If it sounds good, then you are fine.

[The Computer Audiophile]

15 minutes ago, audiophile911 said:

It's been interesting following my thread but except for a couple of posts most have not addressed the fundamental question from my original post.  Is it a bad idea to connect a mac mini directly to my DAC via usb?  I think it sounds good or am I missing something??

I don’t do it, I wouldn’t recommend it, but it isn’t a horrible idea. I say, don’t worry, be happy. 

[beerandmusic]

30 minutes ago, Miska said:

 

Point is that the analog output from both DACs is not the same, it is massively different.

 

back to this....would they be vastly different even if the recording was just a one second 1khz sine wave?

could neither dac reproduce a near perfect 1khz sine wave?

 

[beerandmusic]

6 minutes ago, The Computer Audiophile said:

I don’t do it, I wouldn’t recommend it, but it isn’t a horrible idea. I say, don’t worry, be happy. 

On another note, i wont forget the story I heard where a "best of show" just used an iphone as a source, and nobody knew it....i don't know the details or if it is even true, but several people reported it here.

[sandyk]

32 minutes ago, Miska said:

What kind of DAC do you have? Because SDM (DSD) converters have way more than 95% market coverage in audio ADC and DAC. Also your mobile phone's microphone is a "native DSD microphone", although very few even know about it.

 That is misleading. None of them do what your program does, as well as the need for a very fast processor PC.

I doubt that my i7 Intel processor would even handle this too well. Neither are most speaker systems good enough, let alone the amplification area , although my Class A Preamp/HA  with it's 1.5mHz -3dB bandwidth and my 15W/Ch.  Class A P.A. certainly are.

 

 I do however applaud your initiative to try and get the very best out of normal recordings for those who have the technical ability and wallet to afford it. More research like this is needed.

[davide256]

Mac notebooks are still very commonly used for demos at audio shows... you can do better but its more likely without research to do far worse.

[Miska]

6 hours ago, audiophile911 said:

It's been interesting following my thread but except for a couple of posts most have not addressed the fundamental question from my original post.  Is it a bad idea to connect a mac mini directly to my DAC via usb?  I think it sounds good or am I missing something??

 

No, it is not bad idea. Depends on your DAC and rest of the system if and how much it makes difference to connect to something else instead.

[Miska]

6 hours ago, sandyk said:

 That is misleading. None of them do what your program does, as well as the need for a very fast processor PC.

I doubt that my i7 Intel processor would even handle this too well.

 

Not the same, but something similar, while cutting some corners...

 

But it is a myth that you would need a very fast processor. I can run DSD256 upsampling on a quad-core Atom (Pentium branded). Sure, there are algorithms that can get very heavy, but there are also algorithms that produce already good results on very light CPU.

 

So you would likely get quite far already with i7.

[beerandmusic]

21 minutes ago, Miska said:

 

No, it is not bad idea. Depends on your DAC and rest of the system if and how much it makes difference to connect to something else instead.

Yet, the analog output of a schiit mb dac and and rme adi-2 dac would be "vastly" different even for a recording of a simple 1khz sine wave with all other hardware the same?

[Miska]

1 hour ago, beerandmusic said:

Yet, the analog output of a schiit mb dac and and rme adi-2 dac would be "vastly" different even for a recording of a simple 1khz sine wave with all other hardware the same?

 

Yes..

 

But this is wrong thread and this discussion is getting stuck running in a loop, so better stop here.

[beerandmusic]