Antoine's system

[SwissBear]

I have never tried the USB input on my 800.

As witnessed in this white paper (http://www.audiophilleo.com/docs/Dunn-AP-tn23.pdf), USB is by far not the only digital communication process affected by jittering, and therefore subject to improvement through re-clocking.

[thumb5]

As witnessed in this white paper (http://www.audiophilleo.com/docs/Dunn-AP-tn23.pdf), USB is by far not the only digital communication process affected by jittering, and therefore subject to improvement through re-clocking.

I didn't see any mention of USB in that white paper - am I missing something?

[SwissBear]

As witnessed in this white paper (http://www.audiophilleo.com/docs/Dunn-AP-tn23.pdf), USB is by far not the only digital communication process affected by jittering, and therefore subject to improvement through re-clocking.

I didn't see any mention of USB in that white paper - am I missing something?

The paper was written by a specialist of the AES/EBU protocol, and illustrates the fact that jittering is a problem which affects much more various digital phenomena than USB. Just an attempt to not limit the problem to the improvement of USB sources.

[thumb5]

Understood. Personally I find it much easier to see how jitter can be a problem with AES/EBU than with USB. I took your comment to mean that the paper discussed jitter specifically in the context of USB.

[SwissBear]

Understood.  Personally I find it much easier to see how jitter can be a problem with AES/EBU than with USB.  I took your comment to mean that the paper discussed jitter specifically in the context of USB.

Sorry about the lack of clarity of my expression :-)

[thumb5]

No problem

[SwissBear]

Understood.  Personally I find it much easier to see how jitter can be a problem with AES/EBU than with USB.  I took your comment to mean that the paper discussed jitter specifically in the context of USB.

Sorry about the lack of clarity of my expression :-)

The problem with USB is, if I understand correctly, two folds :
- a huge problem of transmission of HF interference, created by the various components of the PC/Mac, together with the audio information ; this requires a heavy cleaning, often called galvanic isolation, and also probably some filtering.
- a serious problem of short term inconsistency of the clock of the computer which is used to produce the USB signal. Therefore, most solutions to solve this second issue either consist in reclocking as does the Mutec Antoine has purchased, or in plugging the audio data onto a clean signal, as does Acousence, a competitor of Mutec.
Does it make more sense as far as USB is concerned ?

[thumb5]

Up to a point, yes.  The potential for noise injection is pretty clear.  I'm not sure I buy the argument about inconsistencies in the timing of the clock generated by the USB host, especially in the case where the DAC (Devialet) is in asynchronous mode.  But I must add it's not something I've experimented with in any listening tests with so I'm only talking about what I would expect from a knowledge of how the hardware and software work.

Since Antoine said he's using the Mutec as a USB to AES/EBU converter, that doesn't say anything (I think) about whether there would be any sound quality improvement to be gained by re-clocking the USB.  Again...I might be missing something, that's just my --possibly naive -- reading of the story so far.

[SwissBear]

Up to a point, yes.  The potential for noise injection is pretty clear.  I'm not sure I buy the argument about inconsistencies in the timing of the clock generated by the USB host, especially in the case where the DAC (Devialet) is in asynchronous mode.  But I must add it's not something I've experimented with in any listening tests with so I'm only talking about what I would expect from a knowledge of how the hardware and software work.

Since Antoine said he's using the Mutec as a USB to AES/EBU converter, that doesn't say anything (I think) about whether there would be any sound quality improvement to be gained by re-clocking the USB.  Again...I might be missing something, that's just my --possibly naive -- reading of the story so far.

If you are not convinced that cleaning the audio signal by plugging it onto a clean clock signal improves the audio restitution, I guess it becomes something like the debate on cables ; it's a matter of personal experience and appreciation.

In this forum, the Totaldac d1-server, which is nothing else than a linux box connected to an expensive reclocker, has gathered significant interest and appreciation. The Mutec MC-3+ USB is a cheaper version of the same kind of technology, but achieved in a more industrial/audio-pro way. Let's see if this gathers the same kind of positive appreciation than it's prestigious competitor. And let's wait what our German friends have in store for us with the new expected developments of a precision 10 MHz clock by Mutec.

[Pim]

Here's something to contemplate. If it's so obvious that an incoming signal needs 'work done', shouldn't a good DAC maker do that themselves? I guess what I'm trying to say is that if (and that's a big if) all DAC makers solved the problems that are now solved by Regen, Mutec etc. There wouldn't be a market for them.

And that theory could also explain why some people hear bigger differences on their equipment than others, after installing such devices. After all, the best DAC makers out there should know how to deal with 'difficult' data.