Thanks for the reply. The issue is, the hardware doesn't seem to be passing audio to analog automatically. I've got to find some sort of software that will let me take the optical signal, coming in via SPDIF, and push it back out through the speakers. I've poked through Vantek's software and it doesn't seem to have any sort of option for this. Come to think of it, in all the years I've been messing with audio gear, I've never once been able to get sound out of SPDIF/optical. It lights up, but it seems to do nothing at all.
I haven no way of telling if there is a signal coming from the optical cable (should I be able to see the light flickering, or is it impossible for the human eye to perceive?)
I've tried running the optical cable from the TV to the Vantek, thinking maybe the TV will pass through the audio from the HDMI, but again, I have no way of knowing if that damn optical cable is doing anything.
