Audio Switching

[zamproject]

Can you explain further?Both tracks have this? I do know the tracks aren't exactly lined up because I just recorded them and didn't align them but that isn't what you are talking about.

Sample align at start...then on file is 10 samples late at end of files.
This is continuous drift, not missing sample.
With a null test you hear the fade in all long (slow phase shift in high frequency)

Best
Zam

 

[Newmarket]

I would suggest any difference (personally, I can't hear one) is due to the final A/D conversion. Even done with the same pieces of gear, distortion changes particularly with temperature.
There's a quite interesting thread on the Cosmos Discord channel, where the designer of the Cosmos ADC explains how distortion changes; he offers a thermostatic option for his converter.

Did no one tell you that only one parameter may change in a comparative test?

I think the meaning is that both 'new" files were produced with the same parameters. The difference noted relating to the original files posted ?

But will anyway say / agree that there is too much in that signal chain for the testing intended. Better to take the SPDIF straight into a computer direct and via the switcher to compare files for any discrepancies. If no issue then imo you are looking at jitter - both signal and cable related (so different cable lengths etc are a thing here) - and that includes any difference in signal level and slew rate.
I will say that imo the differences here need to be quite large to make an audible difference but YMMV. Much obvs depends on the jitter rejection / reclocking details of the DAC.

 

[scott2000]

I would suggest any difference (personally, I can't hear one) is due to the final A/D conversion

I've tried hard to hear any difference but really can't unless I look at the file names or delay the listening between samples

Did no one tell you that only one parameter may change in a comparative test?

Both new samples are same volume. It wasn't meant to compare the first set of samples with the interface not clocked to the AD. Like Newmarket said.

 

[scott2000]

Sample align at start...then on file is 10 samples late at end of files.
This is continuous drift, not missing sample.
With a null test you hear the fade in all long (slow phase shift in high frequency)

interesting

Better to take the SPDIF straight into a computer direct and via the switcher to compare files for any discrepancies

Will definitely try...

 

[Newmarket]

Imo it's much easier to introduce a problem (that may not be apparent immediately) through some clocking / sync type issue. As the OP has already experienced in posting here.
If Zamproject observations are correct then there's something there that needs bottoming out before proceeding further.

 

[scott2000]

zamproject's observations are correct...
Will try simplifying the chain to play around more...

 

[totoxraymond]

Hi,

I haven't checked the files, but could this drift in time be because files aren't recorded at the same time? So the clock could have drifted a little bit due to temp, or who knows what between each recording?

You would need a perfect spdif splitter to check both path at the same time and see if you could null them out...

Or i could be completely wrong...


Cheers,

Thomas

 

[abbey road d enfer]

Sample align at start...then on file is 10 samples late at end of files.
This is continuous drift, not missing sample.
With a null test you hear the fade in all long (slow phase shift in high frequency)

This can be easily explained by the SR drift between the two recordings. 10 samples is about 1ppm compared to the length of the file. Funnily enough, manufacturers are not very communicative about clock drift, when they are extremely to jitter. I guess it's because drift is not a very important factor of quality loss and jitter has been presented as public enemy number one.
VCXO's are typically in the +/-10 to +/-100 ppm range.

 

[scott2000]

could this drift in time be because files aren't recorded at the same time?

Yes. Was thinking same thing . abbey's comments eluded to this a bit too.

Weird thing, I went direct from cd spdif out to interface clocked to spdif
then cd spdif out to kramer video in/out to interface clocked to spdif and the samples were off but only by 4 samples this time...

Then I saw I haven't updated the interface's drivers in a few years. (hdsp9652) so I updated them. Now I can't get a reliable sync from the kramer atm..... lol...just cuts in and out.. works with internal clock fine...

 

[scott2000]

I reinstalled an older interface driver and the kramer synced fine... Then I reinstalled the latest driver and the kramer synced fine.... of course....

here are the 2 files
one is cd spdif out to interface spdif in using spdif as clock
the other is cd spdif out to kramer video in/out to interface spdif in using spdif as clock



edit....mods....feel free to move this stuff to a new thread if it seems a bit too much..