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USB to I2S conversion and reclocking quality doubt


doraymon

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I am trying to understand a basic issue linked to signal reclocking and I would appreciate some input from the forum.

Suppose I have a Network Player with an excellent clock which outputs a USB signal which then goes into a D/D converter where it is transformed into I2S. 

Also let’s assume that the converter’s clocks are not as good as the player’s.

 

QUESTION:

Does the final I2S signal quality depend in any way from the quality of the signal being input to the D/D converter or the only thing that counts is the D/D converter’s clock accuracy? 

In other words is the D/D converter going to degrade the better “quality” signal received from the player? 

 

Thanks and apologies in se in advance if the question is inaccurate or silly...

NUC10i7 Roon ROCK > EtherREGEN > Lumin U1 Mini > Chord DAVE > Focal Utopia 

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21 hours ago, mansr said:

The output can only be as good as the last clock, in this case that of the D/D converter. Whether or not prior clocks in the chain matter is a hotly debated topic in audio circles. Digital design principles say they shouldn't, and the rest of the world agrees with this. That said, it is probably possible to design a device so horribly that it really is significantly influenced by upstream clocks. If you suspect something to fall in this category, don't buy it.

As a matter of fact I have the opposite problem, that is my upstream devices have supposedly better clocks than the D/D converter.

This is my chain: SOtM sMS-200ultra > SOtM tX-USBultra >(over USB)> Singxer KTE SU-1 DDR >(over I2S)> Holo Audio KTE Spring DAC L3

So the better clocks are upstream and the worst downstream...:S

Essentially the SU-1 is there to take care of the USB to I2S conversion (using its Crystek CCHD-575 clocks).

I could indeed skip the SU-1 and feed the the DAC with the USB signal out of the SOtM devices but than the DAC would in any case internally convert this to I2S, using its internal clocks which are much less precise than the 575's.

So the question is: am I wasting my money in placing $2.2k worth of "USB signal cleaning" devices before the SU-1?

I tried to do some tests by adding/removing the tX-USBultra but due to the limited space I have I can't really do a real time A/B comparison and difference was not immediately perceivable.

To add to the confusion I tried to remove the SU-1 and feed the good quality USB signal to the DAC and contrarily to the theory what I am hearing has slightly more detail, fuller bass and the sound is much less fatiguing.

 

I confess I am lost.

NUC10i7 Roon ROCK > EtherREGEN > Lumin U1 Mini > Chord DAVE > Focal Utopia 

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14 minutes ago, doraymon said:

As a matter of fact I have the opposite problem, that is my upstream devices have supposedly better clocks than the D/D converter.

This is my chain: SOtM sMS-200ultra > SOtM tX-USBultra >(over USB)> Singxer KTE SU-1 DDR >(over I2S)> Holo Audio KTE Spring DAC L3

So the better clocks are upstream and the worst downstream...:S

Essentially the SU-1 is there to take care of the USB to I2S conversion (using its Crystek CCHD-575 clocks).

I could indeed skip the SU-1 and feed the the DAC with the USB signal out of the SOtM devices but than the DAC would in any case internally convert this to I2S, using its internal clocks which are much less precise than the 575's.

So the question is: am I wasting my money in placing $2.2k worth of "USB signal cleaning" devices before the SU-1?

I tried to do some tests by adding/removing the tX-USBultra but due to the limited space I have I can't really do a real time A/B comparison and difference was not immediately perceivable.

To add to the confusion I tried to remove the SU-1 and feed the good quality USB signal to the DAC and contrarily to the theory what I am hearing has slightly more detail, fuller bass and the sound is much less fatiguing.

 

I confess I am lost.

 

I find SU-1 -> I2S to be a slight improvement over Spring USB input, but this depends on too many variables that are specific to individual system and components. If no USB cleaners sounds best to you, that’s the way to go!

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57 minutes ago, doraymon said:

As a matter of fact I have the opposite problem, that is my upstream devices have supposedly better clocks than the D/D converter.

This is my chain: SOtM sMS-200ultra > SOtM tX-USBultra >(over USB)> Singxer KTE SU-1 DDR >(over I2S)> Holo Audio KTE Spring DAC L3

So the better clocks are upstream and the worst downstream...:S

Essentially the SU-1 is there to take care of the USB to I2S conversion (using its Crystek CCHD-575 clocks).

I could indeed skip the SU-1 and feed the the DAC with the USB signal out of the SOtM devices but than the DAC would in any case internally convert this to I2S, using its internal clocks which are much less precise than the 575's.

So the question is: am I wasting my money in placing $2.2k worth of "USB signal cleaning" devices before the SU-1?

I tried to do some tests by adding/removing the tX-USBultra but due to the limited space I have I can't really do a real time A/B comparison and difference was not immediately perceivable.

To add to the confusion I tried to remove the SU-1 and feed the good quality USB signal to the DAC and contrarily to the theory what I am hearing has slightly more detail, fuller bass and the sound is much less fatiguing.

 

I confess I am lost.

You've got too many gadgets,

The DAC's clock will override  them all.

 

And  it's not only the clock.

The  DAC doesn't give an ra how 'improved' the signal is because it isn't really a 'signal' at all in the conventional sense. Basically  it's just  on and off.

 

it's not even interested in the 'edges'  because a lot of the  time there aren't any.

It's not interested in 'measuring' the voltages either,  it just needs to be 'aware' of them. And a lot of the time a 'zero' and a 'one' look exactly the same 'signalwise' as  their   voltages can be the same whatever 'electrical value' ; they are.

 

If in doubt use USB with a  cable  from the local supermarket. If it's got the USB logo on the connectors it meets the USB specification. And that's all the DAC cares about.

 

A picture of a USB signal. It may help to clarify some points  I made.

 

NRZI_example.png

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26 minutes ago, pkane2001 said:

If no USB cleaners sounds best to you, that’s the way to go!

I'm not sure yet, I just started testing.

I was just looking for other people's experience to form an more solid opinion.

 

37 minutes ago, mansr said:

Almost certainly.

O.o

 

NUC10i7 Roon ROCK > EtherREGEN > Lumin U1 Mini > Chord DAVE > Focal Utopia 

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Just now, doraymon said:

I'm not sure yet, I just started testing.

I was just looking for other people's experience to form an more solid opinion.

O.o

 

 

What sounds better to you will depend in a large part on what you are used to hearing. A cleaner, more accurate playback may not sound so good if you are used to slightly more bass or midrange or treble. Even if your findings don't match anyone else's, stick with what sounds best to you.

 

If at all possible, I recommend doing a blind test with and without additional components (SU-1, USB cleaners, etc.) If you can't tell the difference in a blind test, the differences are likely so small as to not to matter.

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54 minutes ago, doraymon said:

I confess I am lost.

How are you powering all this gear?

Pareto Audio AMD 7700 Server --> Berkeley Alpha USB --> Jeff Rowland Aeris --> Jeff Rowland 625 S2 --> Focal Utopia 3 Diablos with 2 x Focal Electra SW 1000 BE subs

 

i7-6700K/Windows 10  --> EVGA Nu Audio Card --> Focal CMS50's 

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2 minutes ago, rickca said:

How are you powering all this gear?

The two SOtM devices (Network Player and USB decrapifier) with a sPS-500 always from SOtM.

The DAC and SU-1 have their own (modded) power supplies.

All units are connected to a mains filter which is only for sources (another one is for the amp section).

Power cords are Ice Age Copper-Copper for the DAC and Audioquest NRG-X3 for the SU-1 and sPS-500.

NUC10i7 Roon ROCK > EtherREGEN > Lumin U1 Mini > Chord DAVE > Focal Utopia 

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I looked back at your posts to figure out how you got here.  So you were using the SOtM sMS-200Ultra and tX-USBultra with a Hugo before you got the KTE Spring, right?  What was your impression of adding the SOtM gear to your chain at that time?

 

Then it looks like you got the KTE Spring L3 followed by the KTE SU-1 DDR, is that right?

 

So when did you most like your sound quality?  You're certainly using components that lots of people seem to rave about.  

Pareto Audio AMD 7700 Server --> Berkeley Alpha USB --> Jeff Rowland Aeris --> Jeff Rowland 625 S2 --> Focal Utopia 3 Diablos with 2 x Focal Electra SW 1000 BE subs

 

i7-6700K/Windows 10  --> EVGA Nu Audio Card --> Focal CMS50's 

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4 minutes ago, rickca said:

So you were using the SOtM sMS-200Ultra and tX-USBultra with a Hugo before you got the KTE Spring, right?  What was your impression of adding the SOtM gear to your chain at that time?

Correct, first impressions were: more depth to the soundstage and in general a more lively sound. No significant change in detail level. 

But I soon sold the Hugo (after placing the order for the Spring) so not a long time to test.

 

16 minutes ago, rickca said:

Then it looks like you got the KTE Spring L3 followed by the KTE SU-1 DDR, is that right?

So when did you most like your sound quality? 

Again correct.

The Spring was a significant improvement over the Hugo. More detail, air and even better transient reproduction. In a word, more realistic.

I haven't tried removing the Network Player/USB decrapfier because with my new setup at home it would be too complicated to access the music server directly.

I did try to remove the SU-1 and didn't experience any degradation. On the contrary some times a very welcome reduction of harshness with some tracks and a punchier bass.

 

NUC10i7 Roon ROCK > EtherREGEN > Lumin U1 Mini > Chord DAVE > Focal Utopia 

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1 hour ago, mansr said:

USB actually encodes 0 as change and 1 as no change, the opposite of this figure. The principle is the same, though.

Good. That obfuscates it even more. Two things, one the opposite of the other, both called NRZI, and the 'I'  can stand for  two different things as well. Who ARE these people?

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When I originally started to play around with DDCs, I figured up-stream quality didn’t matter so much as the DDC’s high quality clock and power supply would output a clean signal. Although that seems intuitive, I found out that was NOT the case; improving the quality of the source (adding an ATX LPSU, removing SSD power, installed a PPA OCXO controller) also improved the quality after the DDC. Indeed, using a 5v battery vs a LPSU on the PPA by itself makes a difference even though you would think the DDC output wouldn’t change.

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Probably the most important step is getting a nordost 9 9s copper mouse and keyboard for the all important click “play”. After all, source first. Obviously you need an upgraded furutech usb socket for keyboard and mouse and hospital grade mouse mat. 

I wouldn’t even think about the rest of the rig until you have the front end sorted. 

You are not a sound quality measurement device

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3 hours ago, adamdea said:

Probably the most important step is getting a nordost 9 9s copper mouse and keyboard for the all important click “play”. After all, source first. Obviously you need an upgraded furutech usb socket for keyboard and mouse and hospital grade mouse mat. 

I wouldn’t even think about the rest of the rig until you have the front end sorted. 

Thanks for your valuable contribution to the thread!

NUC10i7 Roon ROCK > EtherREGEN > Lumin U1 Mini > Chord DAVE > Focal Utopia 

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2 minutes ago, Spacehound said:

You asking a question  or telling us to buy some more magic boxes?

Despite all my efforts I still fail to understand what do you want and why are you asking such questions.

if you are not interested in the topic I am rising whiny don’t you kindly do yourself, myself and all the community a favour and look somewhere else.

NUC10i7 Roon ROCK > EtherREGEN > Lumin U1 Mini > Chord DAVE > Focal Utopia 

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1 hour ago, doraymon said:

 

 

Despite all my efforts I still fail to understand what do you want and why are you asking such questions.

if you are not interested in the topic I am rising whiny don’t you kindly do yourself, myself and all the community a favour and look somewhere else.

What efforts?

I've not asked anything, that's you. And you need to be careful about 'rising whiny'.

I said get rid of them all, with reasons,  (and one with  ten times more expertise than most, agreed).

 

Later I expanded it with further explanations,  advice what interface to use, and a format diagram.

What on earth's wrong with that? Do you do the same  to your wife/physician/accountant?

 

Are you wasting money? The answer's still yes.

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36 minutes ago, Spacehound said:

What efforts?

I've not asked anything, that's you. And you need to be careful about 'rising whiny'.

I said get rid of them all, with reasons,  (and one with  ten times more expertise than most, agreed).

 

Later I expanded it with further explanations,  advice what interface to use, and a format diagram.

What on earth's wrong with that? Do you do the same  to your wife/physician/accountant?

 

Are you wasting money? The answer's still yes.

Apologies I have mistaken you for another member... 

Thanks for your posts earlier, still I don’t understand why are you asking me if I am telling you to buy more magic boxes.

Apart from the irony of the “magic boxes” which implies that I’ve been chasing snake oil, what makes you think I am trying to sell anyone anything? It’s a genuine question, don’t take it as a provocation.

I am here to learn and understand what I’m hearing so I can progress in the pursue of a better sound for me.

Please advise what you see wrong or funny in this approach.

thanks

 

NUC10i7 Roon ROCK > EtherREGEN > Lumin U1 Mini > Chord DAVE > Focal Utopia 

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Yes my question about the risk of wasting money was synthetic but I was obviously interested in understanding the reason behind any statement.

My system is most probably overloaded with "gadgets" which not necessarily improve the sound. Now if we can try to leave aside for a second any comments about me being so naive to buy them, I would be interested in understanding more on how they work and interact so that any further steps I'll take will be guided not only by my ears but also supported by some kind of technical explanation. I hope that's fine withe everyone here.

Unfortunately the more I dig into this the more I get the impression this is kind of an uncharted territory. I read a good post HERE.

I will keep on my quest and in the meantime enjoy my music (as I am doing in this very moment with the epic "Friday night In San Francisco"!

NUC10i7 Roon ROCK > EtherREGEN > Lumin U1 Mini > Chord DAVE > Focal Utopia 

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