Since you have good high end equipment, you might consider a good audio card like the RME Audio DIGI 96/8PAD which has S/PDIF digital outputs (optional AES/EBU balanced digital I/O breakout cable available), good clock synching (for low jitter) and high quality circuitry for minimizing PC EMI noise from within the PC cabinet. This card was reviewed in Stereophile magazine. If this seems like overkill to you, check out the CardDeluxe from Digital Audio Labs. If you want AES/EBU professional quality balanced digital I/O, you can get an optional interface to add on. The CardDeluxe was a Stereophile Recommended Component. For an even lower cost alternative, you can go with an Echo Audio Mia MIDI which only offers S/PDIF digital I/O. Finally, the lowest cost choice would be an M-Audio Audiophile 2496 PCI card which offers S/PDIF digital I/O.