Try the Waveterminal U24--its an external USB to coax converter. While it has a DAC in it, its only about $250, and the coax digital PCM output does not resample to 48 kHz like the M-Audio and Edirol devices, and keeps the signal at 44.1 kHz. It will allow you to use a long run of USB cable, which does not introduce jitter, instead of a long run of coax. I found the sound from my computer went from muted (when I was using an M-Audio Sonica with a long toslink run to the DAC) to spectacular (when I switched to a long USB run to the Waveterminal).
I think the Apogee concept is USB from computer to Apogee, and letting the Apogee to D to A conversion. The Apogee has gotten excellent reviews, but--like you--I already have a DAC I wanted to use (dCS Delius w/o firewire). The Waveterminal is a cheaper solution for us folks.
UV, FYI, if you are running USB to the Apogee, you are bypassing not only the DAC in the M-Audio card, you are bypassing the card itself. The computer will be configured to route audio through the USB port, not a sound card. You don't need an audio card to use the USB option.
I think the Apogee concept is USB from computer to Apogee, and letting the Apogee to D to A conversion. The Apogee has gotten excellent reviews, but--like you--I already have a DAC I wanted to use (dCS Delius w/o firewire). The Waveterminal is a cheaper solution for us folks.
UV, FYI, if you are running USB to the Apogee, you are bypassing not only the DAC in the M-Audio card, you are bypassing the card itself. The computer will be configured to route audio through the USB port, not a sound card. You don't need an audio card to use the USB option.