Why do digital coax cables matter?

Rower - if you are getting bit errors, the eye pattern is so bad that jitter is the least of your concerns.

"reclocking the data at the DAC is the key to superior reproduction"

You would think so, but unless you can synchronize the source to the DAC using word-clock, it is not the best solution. Very few sources have this capability.

You will achieve much lower jitter making the source jitter low and feeding it to a DAC without internal reclocking. This is because all of the techniques for asynchronous reclocking for jitter reduction in DACs are inferior, both PLL and ASRC.

Steve N.
Empirical Audio

...http://www.stereophile.com/reference/1093jitter/...

This is a pretty good description of what is going on. It is an older article but still relevant to many points.

Was just reading about how 1.5m is the best length for a digital cable. Something to do w/ reflections. I read somewhere else that all interconnects can benefit from being 1.5m. Somehow that doesn't sound right to me. So, is it true- will 1.5m RCA interconnects going from my DAC to my pre amp sound better than the 2 ft length I am currently using? Thanks

Mrblackcrow 8-26-2017
I read somewhere else that all interconnects can benefit from being 1.5m. Somehow that doesn’t sound right to me. So, is it true- will 1.5m RCA interconnects going from my DAC to my pre amp sound better than the 2 ft length I am currently using?

You are correct about that not sounding right. The 1.5 meter length recommendation that is often seen for digital cables has no relevance whatsoever to cables conducting analog audio signals. In general, in the case of analog audio cables the shorter the better, if it makes any difference at all.

Also, regarding S/PDIF and AES/EBU digital cables, as you can see in some of the earlier posts in this thread the optimal length is dependent on a great many component and cable dependent variables, some of which are not usually specified (e.g., risetimes and falltimes of the output of the signal source). So 1.5 meters should be considered as having the best odds of being optimal for a digital cable (unless a very short length is practicable, such as 6 or 8 inches), but other lengths may be better in some cases, and there may be some cases where it won’t matter very much if at all.

Regards,
-- Al

Each end of a coaxial cable uses familiar RCA jacks, which are reliable and stay firmly connected.