Digital Cable Choice; how critical is it?


I am a beleiver that analog cables play a big part in a system's sonic performance.

I am giving consideration to adding an external DAC to my system, for the first time. Always using a single box digital source, I have no experience with digital cables.

I really am a music guy & not a computer/techie guy. So, considering that the digital information that runs from the DAC to the Preamp is 1's & 0's or bits & bytes or whatever they are called; how critical is it to the sonic perfromance that I use an elaborate digital cable, as I have done with my analog interconnects?

Is the sound quality affected with the use of different cables, while still in the digital domain?

Your experience is appreciated
barrelchief
Are all of you (Tobias, jeffcott, Jeff_jones) referring to a lack of difference only between 75 ohm cables (either RCA or BNC), or ALL digital data cable including 110 ohm XLR. ST glass, and Toslink (plastic and glass)?
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First of all, difference between digital cables depends on a dac you're going to get. When I had a Bel Canto DAC2, I tried a lot of different digital cables varying in price from $50 to $1000: WireWorld SuperNova 3+ and 5+ Glass Toslink, Acoustic Zen Silver Bytes, Acoustic Zen MC2, Synergistic Resolution Reference, Virtual Dynamics NiteII and Master, Stereovox, and even some Monster. Difference between these cables was alway apparent. I chose Virtual Dynamics NiteII which was the best of the bunch, then I upgraded to Virtual Dynamics Master, which was in a league of its own. There are some dacs though, that don't react to the digital cable changes, so you'll have to try and find out.
If two digital (let's say S/PDIF) cables measure the same, they will sound identical regardless of price, material (copper, silver, gold, palladium, amorphous metal), dielectric or wire configuration. This might be a dangerous statement but I personally don't see why these two cables would sound differently. Do those measurements have limited value with regard to how good the cable will perform?

Chris
Nsgarch - fair question, but my better angel is telling me to just give up, take my toys and go home. If anybody is interested and has a fairly fast internet connection an insight into what is possible to take audiophile concerns (ac line effect, vibration tweaks, digital & power cables, why does my system sound different than it used to, etc.) more toward science is at http://www.dataq.com/applicat/presentation/I_A_hardware-overview.html
Happy listening!
Jeff, thanks for the link. I enjoyed the presentation.

Have you used this device to measure the things you mentioned in your audio system, or it it strictly a work tool?

I've never used anything but AT&T glass. For one thing, the Wadia DAC I used to have just had one glass input! (My new one has several different kinds.) I did try a lot of different AT&T cables though without any impressive differences UNTIL I sprung for an Aural Symphonics Optimism V2 and WOW! What an ear opening experience that was, with slightly different tonal balance depending on which way the cable was oriented. I know, according to your measurements, that should have no effect -- and it didn't with all my other ST cables.

As for 75ohm jobbies, all I know is what I've heard about connectors -- that BNC connections maintain the 75ohm continuity better than RCA connectors and therefore provide a more accurate datastream to the chips. But I don't use metal, so I haven't ever compared.
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