Hi,
Currently, what would be the best audio card with a coax s/pdif input? I´m in the process getting my DATs in FLAC. There are zillions of cards with optical in but my DAT player has coax out and optical in. A 24/192 conversion would be a nice add on.
J
Look for cards designed for professional audio recording and production - here's an oft-cited example, the M-Audio Audiophile 2496:
http://www.m-audio.com/products/en_us/Audiophile2496.html (http://www.m-audio.com/products/en_us/Audiophile2496.html)
Another option would be a cheap coax-to-TOSLink converter box (usually around $20 USD), and then making sure that your sound card/interface doesn't resample its input.
However, why do you want "24/192 conversion"? DATs max out at 16/48.
A basic CMedia job (8738 or 8768/70) with digital I/O is quite suitable for this kind of stuff. Only thing they don't support is 32 kHz... 44.1 and 48 are fine. Not sure whether the open-source drivers are required for bit-perfect recording; I don't think they are, but they wouldn't hurt either.
Alternatively try looking for an Envy24 or Envy24HT based card. The old Terratec Aureon Sky and Space models tend to be going for fairly small money here in Germany, and they'll sync to most everything. You still need a coax to Toslink converter for those, but their Audiotrak relatives with coax I/O are a lot rarer. I don't remember what the situation with the digital I/O was like when using Prodigy 7.1 drivers.
If you also want 24/192 recording, cards like the ESI Juli@ and M-Audio Audiophile 192 will do the job. For something with DSP capability (and Creative driver bloat), you can try the EMU 0404... though I'm not sure whether that's bit-perfect. And of course the trusty Asus Xonar D2(X) also has coaxial I/O.
Another issue: what software to use to record the stream?
(My problem is somewhat different: I have some driver quirkinesses changing the volume of my digital outputs, and would like to feed it different wordlength signals to check what is actually going on. Want an application which can tell me what wordlength the signal has, and which bits of it are actually used.)