Different solutions to usb input

[OldBigEars]

My Chord Qutest is fed by a microRendu 1.4 via a Curious link and it sounds great.  I should probably leave it and just enjoy it. But being exactly like the rest of you I’m curious about what could be gained from a moderate upgrade for Christmas. I’ve got two ideas in mind:  1) Simply replace the mR 1.4 for an OpticalRendu, and feed it from my Etherregen. OR (2) Feed the mR 1.4 via the Curious into a Denafrips Iris DDC, and the optical to the Qutest. The Optical input is said to be the best of its inputs.  
 

There are no trial periods for Denafrips, so you just have to take a chance with their products.  But I’m inclined to think this could be the more effective upgrade.  Anyone out there got  a qualified opinion about this? 

[RikkiPoo]

Using the Iris for USB to I2S was a big big positive with a Terminator Plus. 

 

Another addition that I felt was a big positive was replacing my Curious Cable with Network Acoustics ENO USB Ag and adding the ENO Ag Network Filter.  They offer a 30 day trial.  You would put the Filter between the EtherRegen and microRendu.  I have 2 SOtM dCBL Cat7 cables and an ISO CAT6 LAN filter.  The ENO Ag Network Filter had a bitter impact.  Very little risk in trying one or both for X-mas.

 

I have fiber between an EtherRegen and SOtM sNH-10G, the effect was not as dramatic as the ENO Ag Network Filter.

[davide256]

On 11/4/2020 at 9:56 PM, OldBigEars said:

My Chord Qutest is fed by a microRendu 1.4 via a Curious link and it sounds great.  I should probably leave it and just enjoy it. But being exactly like the rest of you I’m curious about what could be gained from a moderate upgrade for Christmas. I’ve got two ideas in mind:  1) Simply replace the mR 1.4 for an OpticalRendu, and feed it from my Etherregen. OR (2) Feed the mR 1.4 via the Curious into a Denafrips Iris DDC, and the optical to the Qutest. The Optical input is said to be the best of its inputs.  
 

There are no trial periods for Denafrips, so you just have to take a chance with their products.  But I’m inclined to think this could be the more effective upgrade.  Anyone out there got  a qualified opinion about this? 

I have owned microRendu 1.3 and 1.4. As a Roon endpoint Pentium NUC with Audio-linux, powered by  an Uptone Audio LPS 1.2 resolved music much better.

Given the high value of the Qutest DAC I'd say your endpoint is the weaker link and that some research on current endpoints would be a good direction.

[Blake]

I have a Qutest in my headphone setup, as well as the Denafrips Iris D/D.  The Qutest is powered by LPS 1.2. Before I got the Iris, I was using usb input to the Qutest.

 

After the Iris arrived I purchased a cheap Amazon toslink cable.  I felt the Qutest/Iris combo was a nice improvement over the Qutest with usb in.  I later swapped out the Amazon toslink for an Audioquest Vodka toslink, which provided another uptick in sound quality.

 

With Iris and toslink, compared to usb straight in to the Qutest, the sound is smoother, more organic with better air, transparency and more detailed.  You get a better head stage as well- deeper, more well defined.  Importantly the additional detail is not the result of a brighter sound signature.  

 

I was always curious about the toslink input on the Qutest, as the designer Rob Watts says this input on the Qutest is the best.  

[OldBigEars]

4 hours ago, Blake said:

I have a Qutest in my headphone setup, as well as the Denafrips Iris D/D.  The Qutest is powered by LPS 1.2. Before I got the Iris, I was using usb input to the Qutest.

 

After the Iris arrived I purchased a cheap Amazon toslink cable.  I felt the Qutest/Iris combo was a nice improvement over the Qutest with usb in.  I later swapped out the Amazon toslink for an Audioquest Vodka toslink, which provided another uptick in sound quality.

 

With Iris and toslink, compared to usb straight in to the Qutest, the sound is smoother, more organic with better air, transparency and more detailed.  You get a better head stage as well- deeper, more well defined.  Importantly the additional detail is not the result of a brighter sound signature.  

 

I was always curious about the toslink input on the Qutest, as the designer Rob Watts says this input on the Qutest is the best.  

 

@ Blake - your experience looks extremely valid, thanks for your advice. From other posts I thought you had tried (and highly recommend) the much more expensive Denafrips Gaia?  That looks like a terrific combination but I don't need all those connection options the Gaia provides.  I'm curious as to what benefits the Iris can deliver through the Toslink and you've given me much to think about. There's nothing notably missing or wrong with the USB connection but Rob Watts has clearly stated Toslink is the benchmark.

[Blake]

@OldBigEars That is correct.  I have the Gaia in my speaker setup and I have Iris in my headphone setup (these are in two different rooms).  I have had the Gaia since it was first released.  I just recently acquired the Iris.  I have not compared Gaia and Iris head to head.  If you don't need all the input options on the Gaia, then Iris is a great option.  

 

 

 

 

[barrows]

On 11/4/2020 at 7:56 PM, OldBigEars said:

The Optical input is said to be the best of its inputs

Who told you that???

 

The USB input is the best input on the Qutest.  An opticalRendu combined with a Sonore Power Supply would be a significant upgrade over your µR v1.4.  Do not believe the nonsense about USB being "flawed" in some ways, like any input though, it will respond with better sound quality with a better source and cable (same is true for any other input in a DAC).

[barrows]

7 hours ago, Blake said:

the designer Rob Watts says this input on the Qutest is the best. 

When Rob Watts says this, he is referring to comparing USB input fed from a standard commercial computer, not from an audiophile grade USB source, the results of this comparison would be much different if the USB source had a high quality output (ultra low noise power feed, ultra clean data feed with high signal integrity).  Source matters here.

[fds]

While I have never tested the other inputs on my Chord Mojo, I can confirm that its performance gets surprisingly impressive when using USB via an OpticalRendu<-fiber<-OpticalModule<-copper ethernet<-Mac (here all powered by power banks). Along with HQPlayer to upsample PCM to 7xxkHz with sinc-M, closed-form-M or sinc-L on my MacBook, the little Mojo becomes truly outstanding in particular wrt to 3D soundstage and timing. Makes me notice timing inaccuracies on my other significantly more expensive DAC.

[OldBigEars]

12 hours ago, barrows said:

Who told you that???

 

The USB input is the best input on the Qutest.  An opticalRendu combined with a Sonore Power Supply would be a significant upgrade over your µR v1.4.  Do not believe the nonsense about USB being "flawed" in some ways, like any input though, it will respond with better sound quality with a better source and cable (same is true for any other input in a DAC).

He has written extensively about Qutest on Head-fi and from my recollection he has stated that Toslink is the best input. USB almost as good.  I haven’t noted whether he has tested usb with audiophile grade equipment. You would expect that he would have thought of that. But I’ve been thinking about trying oR for some time and may do that to compare in my system vs my mR 1.4. 

[davide256]

Sounds like a point in time discussion to me. Clearly he likes dual BNC best in practice since that’s how M-scaler connects

[OldBigEars]

If you read his many comments on Head-Fi, clearly he recommends Toslink as the benchmark, unless you are connecting an upscaler. The Chord Qutest thread is over 350 pages so you’ll have to do your own reading, but  he posts there quite regularly. His views are not really a question of speculation, though you argue he doesn’t know his own product as well as others do, I guess. 

[fds]

Maybe Toslink is mentioned as it offers galvanic separation from noisy computers as does fiber via optical ethernet? It is nice that he is sharing his insights there so regularly ... guess it does not hurt sales of his designs.

[barrows]

28 minutes ago, OldBigEars said:

His views are not really a question of speculation, though you argue he doesn’t know his own product as well as others do, I guess.

Of course they are.  Note all of the users who report an increase in performance of the Qutest DAC with a high quality linear power supply, even though Rob Watts denies that such a change would make any difference.

 

The point being, the USB source matters.  If one just connects the output of an ordinary laptop computer to a DAC via USB, a ton of noise will come over that connection to the DAC (yes, I have measured this), and in the case of the Mojo, it will also result in a ground loop in most cases (I have a Mojo here and have noted this).  So if one is using an ordinary laptop as a source, the isolation provided by the toslink connection can be an advantage, and this is what Rob Watts is talking about.  But if one is using a high quality USB source, with a clean output (in terms of both noise and USB signal integrity) such as a Sonore Renderer, USB will outperform toslink every time, unless the USB input in the DAC is horrendously bad (and I do not find the Chord USB implementations to be that bad).

 

I would advise people to test this in their own systems, and not take Rob Watts' comments for granted, especially considering he is not talking about using a high quality USB source.

[MarkusBarkus]

...didn't Mr. Watts also say streaming from your phone was about as good as it gets? Not finding the link at the moment. 
 

FWIW: the Qutest sounded much better here on a Farad3 than their SMPS. And the DAVE sounds much better with that goofy 14 dollar SMPS removed and external cabling to a DC4. 
 

Hey Barrows, maybe wrong thread, but big thanks for mentioning the Iconoclast ICs. Just plugged them in and they are sweet. Mark

[barrows]

3 minutes ago, MarkusBarkus said:

...didn't Mr. Watts also say streaming from your phone was about as good as it gets? Not finding the link at the moment. 
 

FWIW: the Qutest sounded much better here on a Farad3 than their SMPS. And the DAVE sounds much better with that goofy 14 dollar SMPS removed and external cabling to a DC4. 
 

Hey Barrows, maybe wrong thread, but big thanks for mentioning the Iconoclast ICs. Just plugged them in and they are sweet. Mark

Yeah, Iconoclast does not have the rest they deserve, yet...  Pretty fantastic cabling regardless of price.  It is kind of funny, if they put some fancy connectors on their 4x4 OCC XLR cable, and charged $10K for 4' pair, I bet everybody would be all over tham and the accolades would be coming in right and left!

[OldBigEars]

4 hours ago, barrows said:

Of course they are.  

 

@Barrows I think you misunderstood...let me put it another way - we don't need to guess or wonder what Rob Watts recommends.  He writes plainly about his products and the various associated pieces of equipment that he finds work best with them.  This is something we don't need to speculate about.  I hope this is clear now?

 

Your point is that Rob Watts is not always right.  Many people have certainly disagreed with his recommendations - such as, that a battery charger is the purest (and, by implication, ultimate) way to power the Qutest. Your theory that Watts limited his testing to computer grade USB products beggars belief, but could of course be true.  Maybe he just hooked up his notepad and called it good?  I've got a hunch he might have tried a few 'audiophile grade' sources - possibly a Sonore Rendu, or something even better - before signing off the product development file for Qutest. He strikes me as a relatively serious engineer.

 

 

[barrows]

5 minutes ago, OldBigEars said:

possibly a Sonore Rendu, or something even better

I am not guessing, I am a fan of Rob Watts' work, and I have read many of the threads which you are referring to, including ones where he has recommended the optical input on various Chord DACs.

 

I am nearly certain that no one from Chord or Rob Watts himself has sampled a Sonore Renderer, we at Sonore would almost certainly be aware of that.  I have never even heard of him using a Networked audio set up?  From the threads I have read where he participates, it appears that a very large percentage of his listening is headphone based with a Hugo 2 and M Scaler, of course I am sure that not all his listening is that way.

 

But I will emphasize, that despite the copious amount of time he contributes to forums (head fi specifically), I have never heard him mention using a source other than a standard commercial computer.  I think it is pretty reasonable to think his comparisons of USB vs. Toslink are via a standard computer only, especially considering the outcome.

 

Again, I encourage users to try the different inputs themselves, and decide for themselves which inputs work the best in their system, in their application, and not just take another person's word for it, whether that other person is Rob Watts, or myself.

[cat6man]

1 hour ago, OldBigEars said:

 

@Barrows I think you misunderstood...let me put it another way - we don't need to guess or wonder what Rob Watts recommends.  He writes plainly about his products and the various associated pieces of equipment that he finds work best with them.  This is something we don't need to speculate about.  I hope this is clear now?

 

Your point is that Rob Watts is not always right.  Many people have certainly disagreed with his recommendations - such as, that a battery charger is the purest (and, by implication, ultimate) way to power the Qutest. Your theory that Watts limited his testing to computer grade USB products beggars belief, but could of course be true.  Maybe he just hooked up his notepad and called it good?  I've got a hunch he might have tried a few 'audiophile grade' sources - possibly a Sonore Rendu, or something even better - before signing off the product development file for Qutest. He strikes me as a relatively serious engineer.

 

 

 

 

At the last canjam meeting in nyc, Rob Watts gave an interesting talk in one of the conference rooms.

When I asked him during Q&A about network devices, digital noise, and power supplies, etc and what did he recommend doing, he told the group that we should just use a usb cable from our cellphones and that would be the best input..........everything else just messes things up.

 

YMMV

[OldBigEars]

2 hours ago, cat6man said:

 

 

At the last canjam meeting in nyc, Rob Watts gave an interesting talk in one of the conference rooms.

When I asked him during Q&A about network devices, digital noise, and power supplies, etc and what did he recommend doing, he told the group that we should just use a usb cable from our cellphones and that would be the best input..........everything else just messes things up.

 

YMMV

was he talking specifically about Qutest? Or just generalizing? 

[asdf1000]

14 hours ago, MarkusBarkus said:

...didn't Mr. Watts also say streaming from your phone was about as good as it gets?

 

Correct, low power consumption battery powered USB source. No chance of ground loop issues.

 

But he says toslink sources with his DACs perform just as well - as jitter is not measurable with his APx555 , even with 2us of jitter  ...