Digital Cable Choice; how critical is it?

You said:

"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;"

didn't you mean the (single) cable that runs from the CD transport (or digital output of a CD player) to the DAC?
And yes it does make a difference.

It's also important what kind of analog IC's you use from the DAC to the preamp and whether they're single ended (RCA) or balanced (XLR). Balanced seem to work better if your preamp has balanced inputs.

It's also important what kind of power cord is used with DACs, CD players, or basically anything with digital processing circuitry in it (meaning even preamps with digital volume controls). It has to be shielded, and it seems that with most digital-to-analog equipment, bigger (wire size) is better for sonics -- although I still can't explain why, because DACs aren't power hungry like most amps.

I also prefer fiberoptic cable (glass AT&T, not plastic Toslink) to metal coax (S/PDIF, RCA, BNC) or AES/EBU (XLR) for a number of reasons, not the least of which it isolates the DAC from the transport electrically. Unfortunately, there's only one really good one and it's a thousand dollars. Three thousand if you own EMM gear, and have enough money left over ;--)
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Nsgarch, you are correct! I obviously had a brain freeze. I am questionning the importance of the single cable that runs from the transport to the DAC.

Regarding the analog cables, I have always run balanced XLR. However, I was considering going single ended, from the DAC to the pre, because my new pre has a single ended (only) "CD Direct" input that supposedly offers better sound than the XLR inputs.

All of my cabling is Kubala-Sosna, which I am VERY pleased with & intend to stay with.

I don't know if Kubala makes digital (75 ohm) ICs, but if they do, stay with them (for RCA or BNC which is the 75 ohm I'm talking about). Otherwise, if you have AES/EBU connectors on your DAC and CD transport/player, those are always preferred over coax S/PDIF (RCA) or BNC (bayonet) IMO. Kubala has those I'm sure.

I don't know about that "CD direct" business. If your new preamp also has balanced inputs, I'd try it both ways. Betcha a new CD you like the XLR better ;--)
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Nsgarch, Toslink cable is now available with GLASS stranding. Glass Toslink made a HUGE improvement over the cheapo plastic Toslink. And this was in a relatively modest system!

Hi Mike -- That's not a surprise. Glass Toslink has almost twice the bandwidth as plastic. But its practical length is still only 5 meters, while AT&T ST cable can go up to 100 Km between repeaters (for those REALLY large listening rooms ;--)

The real issue with Toslink (for audio, that is) the poor quality of the little transceiver units. They cost about $5 wholesale (STs cost about $120 wholesale) and the quality of their signal output is affected by end-to-end reflections in the cables (another reason to use glass if you can) and transmission jitter (glass won't help with that.)

It can't ever beat AT&T, but whether a glass Toslink connection would outperform a high quality coax (RCA) or aes/ebu (XLR) I really don't know. It would be easy enough to try though, because today, almost all stuff that has Toslink has coax inputs/outputs well.

Here's a little Toslink history if you're interested:

http://www.audioholics.com/techtips/audioprinciples/interconnects/toslink.php
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