Now I understand that the cheapest soundcard with digital optical-in does not make a perfect bit for bit copy (although I don't understand why).
Some sound card manufacturers will re-clock the signal, which means they have to take the bits interpret them, then spit them out again. Why??? because they use an inferior design (just my opinion).
What I'd like to know is what's wrong with a soundcard like the Creative Soundblaster Audigy Platinum 2?
Don't use it, or a wintel box, so can't help you here. But Creative has had one of the worst track records for re-clock digital input of the "major" card manufacturers. I'm sure somebody else will fill you in on this one.
Why do you tapers insist on much more expensive soundcards by manufacturers I've never heard of? I'm not having a go at you or anything, I'm just curious as to how you decide what is a worthwhile soundcard, and what isn't.
Well this is a tough one. One could say that about a lot of the mics, preamps, mixers, etc. that tapers use. To the casual PC user we're all using exotic sound cards, but when you price out things, they probably aren't that much more (ok, mine is, but then I've got 8 analog inputs, 2 digital inputs, word clock, and ADAT)... What makes a great sound card? One that contains a decent A/D & D/A chip, has the right I/O for your project and one that sound like the material you put into (or generated) out of it.
If all you're worried about is Digital to Digital, then just make sure the soundcard doesn't resample and you should be set. Your needs and mine obviously aren't the same, so there isn't any reason for you to plunk down $900 for a MOTU unit/card. Go for what you think you need. To use another analogy. When you need to cut wood, do you use a miter saw, hand saw, or table saw? Depends on your needs and budget. If your not going to cut a lot of wood, a hand saw might be exactly the tool you need. It's the same for sound cards. No need to spend 1K for a sound card if you're only going to use 1/10th of the features.
Hope this helps.
Wayne