This is a technical post, so tender souls may skip 2 the EASY SECTION @ the bottom.
A few points:
AES / EBU is perfectly ok 2 use when referring 2 digital audio cuz its a global standard of the Audio Engineering Society
and the Europian Broadcasting Union
References can b found in both AES
I think Ive wrote it b4 ~ a zillion times but what the !@#%:
Because both SPDIF and AES carry clock + audio they r both susceptible 2 jitter.
Best solution is syncing by means of wordclock blah blah blah.
Jitter will b heard only @ the D/A stage, so thats the best source 4 house clock.
As 4 the cable issue, I find toslinks (plastic) sound worse than glass and coaxials (when no wordclock is used of course).
Different media DO NOT SOUND THE SAME in this case. Optics sound thinner, due 2 jitter.
SPDIF (IEC 60958) is a jungle. Standard voltage is 0.5 V p>p, which is relatively low, so some computer CD-ROM players use much higher voltage 4 s/n reasons and mark it as SPDIF, which will drive any true SPDIF input crazy.
I agree 0.5V is low 4 practical reasons but Sony and Phillips never planned it 4 computer boards or long cables.
1V IMHO would make a good compromise, raising signal quality, and well accepted by standard equipment. Raise ur voltage kids, it will sound better.
(The simple conclusions 4 the easy riders):
Wordclock good. No wordclock worse.
Sync wordclock from the D/A internal clock.
If no wordclock used use coaxial rather than optical.
Keep all AES/EBU connections @ 110Ohms, SPDIF @ 75.
Raise (or lower...) SPDIF voltage 2 1V or have some1 do it 4 U.
Dont drink water after eating fruit.