Alright, so say I get one of the older X-Fi's that can decode it (I've seen a Platinum and I think I found an Elite Pro without the I/O box online), but it doesn't have an S/PDIF connector (I may have missed it, but still). Can I hook up my consoles audio to my motherboard's Optical/Coaxial In...

I was wondering if someone could confirm/correct me as to if my plan will work. I'm hoping to fit all of my needs with just a sound card without also buying a Mixamp or giving up games that support DirectSound3D/OpenAl. Also, at the moment the only headphones/headset I have are some portable...