Digital Cable Choice; how critical is it?

My experience has been that most digital cables do sound different and that it's not necessarily a matter of cost. Please remember that a bit stream (0's and 1's) is NOT traveling down the cable, but an analog waveform with peaks and valleys that gets sampled and turned back into 0's and 1's. So anything that can effect an analog cable can effect a digital cable. In fact, some of the best digital cables I have heard (at least metal S/PDIF cables) are really analog cables at heart. So keep that thought in mind when auditioning cables. FWIW, the best performing S/PDIF cables I have heard are the Audio Note Pallas, the Locus Design Core, the Apogee Wyde Eye, and the Kondo Sounds Labs KSL-LP, most of which are terminated with RCA's (in my case).

"As for clocking.....a cable, being a passive device, physically cannot add "jitter". Length and electrical properties will of course modify the absolute timing and shape of the clock signal but a constant shift is NOT of concern, as audible jitter issues come from VARIATIONS in the clock signal between ticks."

Everyone thinks they are an expert. You are incorrect. Read this white-paper:

http://www.positive-feedback.com/Issue14/spdif.htm

Important aspects for a S/PDIF coax cable:

1) length
2) characteristic impedance
3) terminations
4) conductor sizes
5) geometry
6) metallurgy
7) dielectric materials

Steve N.
Empirical Audio

"Please remember that a bit stream (0's and 1's) is NOT traveling down the cable, but an analog waveform with peaks and valleys that gets sampled and turned back into 0's and 1's."

This is certainly true, however the analog nature alone of ALL signals is NOT the main reason why digital cables often sound different. This has specifically to do with digital circuits and how they treat the signal versus analog circuits.

Digital circuits detect transitions in signals and make decisions based on this. The detection of these transitions is not an absolute thing. There is uncertainly involved because of the imperfect voltage references, ground noise and voltage noise. Slow risetimes in the signal can increase the uncertainty, making it much worse. Reflections can superimpose on the signal shifting it in time.

Steve N.
Empirical Audio