Differences in sound: DAC vs. DAC + Pre-amplifier

[Qhwoeprktiyns]

3 minutes ago, barrows said:

Umm, what debate would that be?  

 

You can start by reading this: https://www.diyaudio.com/forums/digital-line-level/79452-building-ultimate-nos-dac-using-tda1541a-post6031506.html

[Qhwoeprktiyns]

12 minutes ago, barrows said:

I am really unsure as to what your motivation is here?  It is generally accepted that it is proper engineering to isolate noisy digital audio interfaces which include high speed processing chips (USB or ethernet qualify for this) and most well implemented USB DACs, and some Ethernet DACs do exactly that: I am not exactly advocating for anything controversial here.  Is there some other approach which you would advocate for or something, or are you just looking to create Internet based tensions?

 

Why are you questioning my motivation ? 

 

I am not challenging the fact that isolating noisy digital audio is "proper engineering" - please don't misquote me. I am challenging the fact that you are "selling" in most of your posts a given "architecture" based on solutions which are unproven and debated.

 

The fact that you have worked 20 years in audio changes nothing to that. Sorry

[barrows]

19 minutes ago, hopkins said:

Why are you questioning my motivation ? 

 

I am not challenging the fact that isolating noisy digital audio is "proper engineering" - please don't misquote me. I am challenging the fact that you are "selling" in most of your posts a given "architecture" based on solutions which are unproven and debated.

I questioned your motivation because I had no idea why you would challenge what is fairly basic, accepted, best practice for implementing digital receivers without citing any other approaches of note.

 

I did not misquote you, any quotes i posted were taken directly from your posts?

 

OK, so experience counts for nothing with you, I must say i do not really get that: say your getting a heart transplant, would you rather have a surgeon who has done the procedure before, or a first timer?

 

I will take a look at the thread you reference.

 

And by the way, i am not "selling" anything here.  I currently have no affiliation with any company which produces any commercial DAC for sale.  My opinions are my own, as the result of my experiences and the experiences of the engineers I have discussed the subject with over the years.

 

I would disagree that isolating USB (as well as ethernet) interfaces is an "unproven" approach.  It is actually well proven by many, many companies making DACs.  In fact, most of the better DACs available use this approach, and if one measures carefully, for things like USB packet noise, for just a single example, one can show in measurements that well engineered isolation reduces noise in a DAC's output.

 

[Qhwoeprktiyns]

17 minutes ago, barrows said:

I questioned your motivation because I had no idea why you would challenge what is fairly basic, accepted, best practice for implementing digital receivers without citing any other approaches of note.

 

I did not misquote you, any quotes i posted were taken directly from your posts?

 

OK, so experience counts for nothing with you, I must say i do not really get that: say your getting a heart transplant, woudl rather have a surgeon who has done the procedure before, or a first timer?

 

I will take a look at the thread you reference.

 

And by the way, i am not "selling" anything here.  I currently have no affiliation with any company which produces any commercial DAC for sale.  My opinions are my own, as the result of my experiences and the experiences of the engineers I have discussed the subject with over the years.

 

I would disagree that isolating USB (as well as ethernet) interfaces is an "unproven" approach.  It is actually well proven by many, many companies making DACs.  In fact, most of the better DACs available use this approach, and if one measures carefully, for things like USB packet noise, for just a single example, one can show in measurements that well engineered isolation reduces noise in a DAC's output.

 

 

Once again. I am not challenging the NEED to isolate, but how it is done and what results it achieves. 

 

If i were to get a heart transplant I would prefer going with a surgeon who has a proven track record. 

 

I am not saying experience NEVER counts (please stop putting words in my mouth), I am just trying to understand how you substantiate your claims, since every other thread on digital audio in this forum seems to be a platform for you to express them. Digging a little deeper is not a crime. 

[EvilTed]

@barrows

 

Actually the X1 is NOT a DAC.

It is a network streamer, so it negates the need for Ethernet renderers such as Sonore or SotM.

It has optical network input, so it is comparable to the OpticalRendu from an isolation point of view.

 

I thought the debate was whether DAC with digital volume (LeedH or not) sounds better than DAC with Preamp.

In my system, DAC without preamp sounds a tad anemic and thin.

I prefer a tube preamp with NOS tubes, but that's my taste.

 

 

 

[barrows]

 

@hopkins, are you associated with EC designs?  If so, you probably should reference such in your signature.

 

I took a quick look at their website, and I find it kind of confusing that at first they criticize USB, but then their interface is just a D-D converter form USB to toslink?  Weird way to go if you think USB is problematic in the first place.

 

I have zero interest in anything that has anything to do with Toslink, there are MUCH better optical interfaces available, and even if their interface has incredibly good output, it will be compromised by the cheap Toslink receiver on any DAC (I assume they make something better on their own DAC).

 

Also, interfaces which are sample rate limited are of no interest to me.  I prefer higher rate DSD so all this and R2R PCM specific DACs hold no interest for me as well.  Although if one must use PCM, a really good R2R approach can sound nice.

 

Measurements do not show most of the problems they claim there can be with USB when good isolation is implemented, they just seem to claim such and offer no evidence.  I would expect their optical isolation of USB to work well if they implemented it well, such an approach could be used inside any DAC of course.  And it could be applied to an Ethernet interface as well: i look forward to seeing actual measurements showing that this approach improves on already accepted approaches in wide use.

I do believe ground loops can be a problem with USB: this depends the source used: I prefer a USB source which is floating for the USB output for this very reason: some DACs will be sensitive to this, some will not-certainly with DACs which have non-isolated USB interfaces ground loops can be an issue.  But if the USB source is floating, there is no problem.

[Qhwoeprktiyns]

8 minutes ago, barrows said:

 

@hopkins, are you associated with EC designs?  If so, you probably should reference such in your signature.

 

I took a quick look at their website, and I find it kind of confusing that at first they criticize USB, but then their interface is just a D-D converter form USB to toslink?  Weird way to go if you think USB is problematic in the first place.

 

I have zero interest in anything that has anything to do with Toslink, there are MUCH better optical interfaces available, and even if their interface has incredibly good output, it will be compromised by the cheap Toslink receiver on any DAC (I assume they make something better on their own DAC).

 

Also, interfaces which are sample rate limited are of no interest to me.  I prefer higher rate DSD so all this and R2R PCM specific DACs hold no interest for me as well.  Although if one must use PCM, a really good R2R approach can sound nice.

 

Measurements do not show most of the problems they claim there can be with USB when good isolation is implemented, they just seem to claim such and offer no evidence.  I would expect their optical isolation of USB to work well if they implemented it well, such an approach could be used inside any DAC of course.  And it could be applied to an Ethernet interface as well: i look forward to seeing actual measurements showing that this approach improves on already accepted approaches in wide use.

I do believe ground loops can be a problem with USB: this depends the source used: I prefer a USB source which is floating for the USB output for this very reason: some DACs will be sensitive to this, some will not-certainly with DACs which have non-isolated USB interfaces ground loops can be an issue.  But if the USB source is floating, there is no problem.

 

No, I am not associated in any way with ECDesigns. I am a consultant, like you, but in IT - nothing to do with audio.

From the summary you give, I suggest you spend a little more time reading the link I gave you.

 

P.S. If you are not affiliated with any audio companies, why does your profile state "Product Development Consultant with SONORE" ?

[barrows]

22 minutes ago, EvilTed said:

Actually the X1 is NOT a DAC.

It is a network streamer, so it negates the need for Ethernet renderers such as Sonore or SotM.

It has optical network input, so it is comparable to the OpticalRendu from an isolation point of view.

 

Semantics: I would say it is a DAC with an Ethernet input.  Like I said, i am very familiar with the X-1, and I like the way it sounds.  But a DAC cannot compared directly to a Renderer, as the performance of a Renderer has to include whatever DAC and cable it is connected to .

I am glad that you like your preamp!

[barrows]

3 minutes ago, hopkins said:

 

No, I am not associated in any way with ECDesigns. I am a consultant, like you, but in IT - nothing to do with audio.

From the summary you give, I suggest you spend a little more time reading the link I gave you.

Yeah, i read the entire post.  Lots of words, but zero measurements.  Like i said, it might be interesting to use their approach to isolate the Ethernet or USB input in a DAC, and then measure compared to conventional approaches using isolation chips.  I would like to see that comparison.  So far, the measurements I have seen of conventional isolation approaches do not exhibit the large amounts of high frequency noise and poor ground isolation which EC Designs claims.  But if their approach is really that superior in terms of isolation, I am all for it and getting it in a package which can be reasonably implemented to isolate the Ethernet or USB input inside a DAC.  Optocouplers are already used for this by some companies of course, but increasing the distance of the input side to the output side should reduce capacitive coupling, whether this actually results in a meaningful difference needs to be proven.  

[Qhwoeprktiyns]

23 minutes ago, barrows said:

Yeah, i read the entire post.  Lots of words, but zero measurements.  Like i said, it might be interesting to use their approach to isolate the Ethernet or USB input in a DAC, and then measure compared to conventional approaches using isolation chips.  I would like to see that comparison.  So far, the measurements I have seen of conventional isolation approaches do not exhibit the large amounts of high frequency noise and poor ground isolation which EC Designs claims.  But if their approach is really that superior in terms of isolation, I am all for it and getting it in a package which can be reasonably implemented to isolate the Ethernet or USB input inside a DAC.  Optocouplers are already used for this by some companies of course, but increasing the distance of the input side to the output side should reduce capacitive coupling, whether this actually results in a meaningful difference needs to be proven.  

 

I assume there is a good reason why their optical isolation is placed at the DAC's input, and that the USB processing is done before the optical signal is send to the DAC. You can enquire about that with them, I cannot comment on your speculations.

 

As for "sample limited" versus DSD, perhaps you should keep an open mind about that as well, given that you have probably only heard digital with "less than perfect" isolation (to quote you). 

 

[barrows]

4 minutes ago, hopkins said:

As for "sample limited" versus DSD, perhaps you should keep an open mind about that as well, given that you have probably only heard digital with "less than perfect" isolation (to quote you). 

Not gonna happen.  DSD is the superior format for me.  Especially with the ability to oversample with a powerful computer, fully isolated from the audio system (in another part of the home, connected by optical fiber).

I have now heard 4 different types, of discrete, DSD DACs at home, and every one of them had a big advantage over any PCM DAC, including discrete and chip based R2R.  DSD has the advantage of allowing for such a simple, low noise conversion stage, which is still actually linear (unlike R2R).  Everyone of these discrete DSD DACs, while being different in overall performance aspects had a naturalness and ease to their sound quality, that I just do not ever hear from PCM, and that was regardless of the isolation between the USB interface and the DAC, a couple of them I listened to with no isolation at all, and still that natural sound quality prevailed.

I am open minded, but I am not going backwards.  I have tired a lot of things and good sound can be achieved a lot of different ways, but I kept coming back to the discrete DSD converter approach because it offered a sound quality nothing else shared.  Now the trick is to optimize the approach.

 

 

[Qhwoeprktiyns]

Never heard a DSD DAC, but would certainly like to audition one someday. 

[ericuco]

1 hour ago, hopkins said:

Never heard a DSD DAC, but would certainly like to audition one someday. 

Holo Cyan DSD version for one.

[Qhwoeprktiyns]

Actually I did listen briefly to the Mola Mola Tambaqi, which does internal conversion to DSD, in a good setup at a reviewer's house. While it is a good DAC, in comparison to another high end DAC that was being used that day I would mot say it was a night and day difference. There are so many aspects in which a DAC can go wrong or do things right... 

[opus101]

12 minutes ago, hopkins said:

Actually I did listen briefly to the Mola Mola Tambaqi, which does internal conversion to DSD, in a good setup at a reviewer's house. 

 

From my reading of Mola Mola's technical blurb, it isn't DSD. Its PWM quantized at 100MHz.

[matthias]

1 hour ago, hopkins said:

While it is a good DAC, in comparison to another high end DAC that was being used that day I would mot say it was a night and day difference.

 

Which another high end DAC was being used that day?

Thanks

 

Matt

[Qhwoeprktiyns]

I forget, sorry. It was a brief listening session. 

[Summit]

17 hours ago, barrows said:

Yeah well, my experience is the opposite, and there is also absolute zero technical evidence to support the above, in fact every technical metric points in the opposite direction.

 

No matter how ridiculously sophisticated a custom server is, it can NEVER have a noise profile which is as low as that of a properly designed and engineered Ethernet Renderer, it is just not possible.  So, if one prefers the sound of a server to the properly designed and implemented Ethernet renderer, the only logical conclusion that one can draw, is that one is preferring the noisier component, and the extra artifacts which the DAC produces when connected to the noisier component.

 

 

Can you show me evidence (measurements or listing evaluations) to support that Ethernet Renderer is better than SOTA server like Innuos Zenith se, Innuos Statement or Extreme?

 

Technical evidence I don’t know, but one principle I consider to be of great importance is that it’s better to attempt to NOT let the noise “come in” than to clean it up later down streams.

[matthias]

24 minutes ago, Summit said:

 

Can you show me evidence (measurements or listing evaluations) to support that Ethernet Renderer is better than SOTA server like Innuos Zenith se, Innuos Statement or Extreme?

 

Technical evidence I don’t know, but one principle I consider to be of great importance is that it’s better to attempt to NOT let the noise “come in” than to clean it up later down streams.

 

Exactly,

listening experiences with the Taiko Extreme showed that direct connection of a DAC via USB is superior to Extreme plus HQ endpoint connected to the same DAC.

IMO, there is no evidence at all that the endpoint concept is superior sounding, quite the contrary. 🙂

 

Matt

[The Computer Audiophile]

1 hour ago, matthias said:

 

Exactly,

listening experiences with the Taiko Extreme showed that direct connection of a DAC via USB is superior to Extreme plus HQ endpoint connected to the same DAC.

IMO, there is no evidence at all that the endpoint concept is superior sounding, quite the contrary. 🙂

 

Matt

Your experience or that of a couple guys on another site?

 

Endpoints are best in my experience. 

[matthias]

37 minutes ago, The Computer Audiophile said:

Your experience or that of a couple guys on another site?

 

Endpoints are best in my experience. 

 

I have not yet an Extreme.

The listening impressions are from experienced guys here and on WBF.

 

Matt

[barrows]

2 hours ago, Summit said:

Technical evidence I don’t know, but one principle I consider to be of great importance is that it’s better to attempt to NOT let the noise “come in” than to clean it up later down streams.

Exactly, and by using Ethernet you keep noise from the server coming in.  Specifically, best practice is to use optical fiber Ethernet.  No matter what extremes one goes to trying to make a server as silent as possible, that server will never be as silent as well designed Renderer.  I suggest, that the better approach, is not bother about making the server silent.  Put it in another part of the home, and do not let its electrical noise to get to the audio system, by sending the music to the audio system over Ethernet (which is isolated by transformers), or even better, with optical fiber Ethernet (which does not pick up and carry electrical noise at all).

The the only noise which gets to the audio system is that generated locally, in the audio system.

 

There is another big advantage to Networked Audio as well:  You can do as much processing in the server as you may want, run room correction, for example, or much more sophisticated oversampling programs like HQPlayer (which can be a big sonic advantage, especially HQPlayer oversampling and a simple DAC which does no additional processing onboard, reducing noise in the DAC even further).  All this processing in the server makes a lot of noise, but by isolating the server away form the audio system, connected by only an optical fiber cable, the noise never gets to the audio system.  

[barrows]

2 hours ago, matthias said:

IMO, there is no evidence at all that the endpoint concept is superior sounding, quite the contrary.

There is no possible technical explanation for why this would be so.  and it is entirely contrary to my, and thousands of others' experience.  No matter what extremes one goes to, a server can never have a s low a noise profile as well designed Renderer connected by optical fiber Ethernet.  The server, by definition, generates a larger noise profile.

I would suggest that the above expressed viewpoint is an outrageous one, not supported by any valid technical theory, and as such would be in opposition to any accepted understanding of how electrical systems, and audio systems actually work.  In order to support such an outrageous claim, I would suggest that a lot more than listening impressions of a few people would be required.

Can you provide any technical theory for this claim?

Can you provide any measurements showing how this approach could possibly make any DAC perform better?

 

[Qhwoeprktiyns]

35 minutes ago, barrows said:

Exactly, and by using Ethernet you keep noise from the server coming in.  Specifically, best practice is to use optical fiber Ethernet.  No matter what extremes one goes to trying to make a server as silent as possible, that server will never be as silent as well designed Renderer.  I suggest, that the better approach, is not bother about making the server silent.  Put it in another part of the home, and do not let its electrical noise to get to the audio system, by sending the music to the audio system over Ethernet (which is isolated by transformers), or even better, with optical fiber Ethernet (which does not pick up and carry electrical noise at all).

The the only noise which gets to the audio system is that generated locally, in the audio system.

 

There is another big advantage to Networked Audio as well:  You can do as much processing in the server as you may want, run room correction, for example, or much more sophisticated oversampling programs like HQPlayer (which can be a big sonic advantage, especially HQPlayer oversampling and a simple DAC which does no additional processing onboard, reducing noise in the DAC even further).  All this processing in the server makes a lot of noise, but by isolating the server away form the audio system, connected by only an optical fiber cable, the noise never gets to the audio system.  

 

Using optical fiber and thinking it actually provides isolation is complete nonsense because you are still putting an ethernet chip inside the DAC. 

 

There are no measurements to back up the fact that this is a superior solution. 

 

 

 

[Summit]

1 hour ago, The Computer Audiophile said:

Your experience or that of a couple guys on another site?

 

Endpoints are best in my experience. 

 

Have you compared your preferred Endpoints to a SOTA server like Grimm Audio MU1, Innuos Statement or Extreme?