Ji-Ji-Ji-Jitter

[krabapple]

The only thing I "can't be bothered with" is buying equipment and/or hiring someone to conduct a double blind experiment (i.e. throwing even more time and money to diagnose a problem that no longer exists since I changed the settings). I also marvel at those who, for all I know, have no background in psychology attempting to diagnose confirmation bias or the placebo effect from a forum post. As far as I can tell, no one has the exact same setup as me (though at least one person was able to find a copy of my worst test CD) and no one is listening with my ears. I used to see this kind of thing all the time in my IT sideline, where techs were quick to blame the end user and, nine times out of ten, there turned out to be a genuine problem (although, as often as not, the suspected cause was not what any of us expected).

I have (in lieu of a major) a double minor in psychology and music from an Ivy League college. Does that count?

No one cares about your setup and ears and it's not required to replicate them. What's required to diagnose what might be a 'genuine problem' is better data than your anecdotes. Which currently do not rule out simple bias or output level difference.

 

[Hayabusa]

I have (in lieu of a major) a double minor in psychology and music from an Ivy League college. Does that count?

No one cares about your setup and ears and it's not required to replicate them. What's required to diagnose what might be a 'genuine problem' is better data than your anecdotes. Which currently do not rule out simple bias or output level difference.

Oh, aren't we nice..

 

[Sokel]

To put the last nail on the coffin of if the DPLL affects USB I used another ESS DAC with 9038q2m controlled by ESS controller but this time I made it so it was connected with 5 meter UNcertified USB cable (although it states it has a repeater) .

At default setting (5,look at my previews posts at this thread) I had interruptions/slight pops every 3 seconds or so (but consistent).
To make it suffer a little more I lowered the setting to 1 were simply didn't play,the result was something between static and pops.

I had to go to 10 to play decently.

Thing about it is that is unclear if that happens to all but the doubt is enough to try I think.
IF it does it would be nice for the setting to be exposed the same way filters does for example.
Maybe some will misuse it lowering it to zero and then complain but well...

 

[kchap]

To put the last nail on the coffin of if the DPLL affects USB I used another ESS DAC with 9038q2m controlled by ESS controller but this time I made it so it was connected with 5 meter UNcertified USB cable (although it states it has a repeater) .

At default setting (5,look at my previews posts at this thread) I had interruptions/slight pops every 3 seconds or so (but consistent).
To make it suffer a little more I lowered the setting to 1 were simply didn't play,the result was something between static and pops.

I had to go to 10 to play decently.

Thing about it is that is unclear if that happens to all but the doubt is enough to try I think.
IF it does it would be nice for the setting to be exposed the same way filters does for example.
Maybe some will misuse it lowering it to zero and then complain but well...

I'm not sure what the "ESS Controller" is, but before we can pass comment we would need to know more drtail on DAC configuration. When you look at the data sheet for the for the 9038q2m it can support many modes. Is the USB receiver chip set supplying Synchronous, ASRC or Asynchronous data?

Even in Asynchronous mode is the 9038q2m the primary clock or is the USB chip set the primary.

 

[Sokel]

I'm not sure what the "ESS Controller" is, but before we can pass comment we would need to know more drtail on DAC configuration. When you look at the data sheet for the for the 9038q2m it can support many modes. Is the USB receiver chip set supplying Synchronous, ASRC or Asynchronous data?

Even in Asynchronous mode is the 9038q2m the primary clock or is the USB chip set the primary.

Look at post #76 and #78.
You can download the ESS controller datasheet here

Device under test is Khadas TB which you can find very detailed schematics and implementation here

 

[KSTR]

I'm not sure what the "ESS Controller" is, but before we can pass comment we would need to know more drtail on DAC configuration. When you look at the data sheet for the for the 9038q2m it can support many modes. Is the USB receiver chip set supplying Synchronous, ASRC or Asynchronous data?

In the KTB the XMOS USB-Transceiver runs standard asynchronous mode, that is, it is the clock master and it has two clocks the usual rates are derived from, one 45.xxx MHz and a second 48.xxx MHz.

But the 9038q2m runs in async mode off of a local 100MHz crystal, resampling any incoming data regardless of source. At low DPLL setting the result is unstable even with a basically jitter-free master clock as fed from the XMOS.
The crystal-based clock is not very stable to begin with (compared to a true oscillator chip with a low noise supply) and it is brutally sensitive to vibration as well