[Pars]

Quote:

Originally Posted by nick_charles /img/forum/go_quote.gif I have done some limited coax vs optical tests, I did not find any significant differences with my DAC. I do have a few different runs of digital coax I can test out indirectly none are terribly short though, but I have no way of verifying whether they really are 75ohm or not, nor though do I have any way of measuring the resultant jitter or if any differences in waveforms are connected with jitter.

The important point is if you have any that are at least 1.5m, preferably longer. The impedance is important as well, but the interface impedance on either piece of equipment is probably not done correctly anyhow, so until that was corrected, cable impedance is a crapshoot.

 

[tfarney]

Quote:

Originally Posted by Pars /img/forum/go_quote.gif The important point is if you have any that are at least 1.5m, preferably longer. The impedance is important as well, but the interface impedance on either piece of equipment is probably not done correctly anyhow, so until that was corrected, cable impedance is a crapshoot.

What's the importance? If your runs are too long or your impedance is not correct, is enough jitter generated to get into the audible range?

Tim

 

[Pars]

Quote:

Originally Posted by tfarney /img/forum/go_quote.gif What's the importance? If your runs are too long or your impedance is not correct, is enough jitter generated to get into the audible range? Tim

Reflection from impedance mismatch. Too short and the reflection may arrive at the moment a timing transition is occurring. 1.5m is the recommended minimum length for a digital coax... I'd probably go 2m just to be safe. Longer won't hurt. Short is bad. So if you really want to see if you can hear any difference, try a really short cable vs. 2m.

 

[nick_charles]

Quote:

Originally Posted by Pars /img/forum/go_quote.gif The important point is if you have any that are at least 1.5m, preferably longer. The impedance is important as well, but the interface impedance on either piece of equipment is probably not done correctly anyhow, so until that was corrected, cable impedance is a crapshoot.

Um, I followed a debate about this on ProSoundWeb last year or maybe the year before, the consensus was that this was not actually correct and that within reasonable limits the length really made no difference and that certainly 1.5m was no better than 1m. I will see if I can hunt it down.

 

[Pars]

I'll defer to something along these lines:
DIYHiFi.org • View topic - Parallel SPDIF outputs

 

[nick_charles]

Quote:

Originally Posted by Pars /img/forum/go_quote.gif I'll defer to something along these lines: DIYHiFi.org • View topic - Parallel SPDIF outputs

This is the thread I was reading

PSW Recording Forums: Dan Lavry => Why longer is generally better for an S/PDIF Digital Cable

 

[Know Talent]

"Jitter is the sound of one hand clapping"

 

[tfarney]

Quote:

Originally Posted by Know Talent /img/forum/go_quote.gif "Jitter is the sound of one hand clapping"

Or wallets flapping.

Tim

 

[bigshot]

Jitter is a hoodoo.

See ya
Steve

 

[Budgie]

This thread is giving me "the jitters".

 

[ecclesand]

It sounds like:

Ji Ji Ji Jitterbug....<snap> <snap> <snap>....Ji Ji Ji Jitterbug....