SPDIF sound Problem

i am using win 7 connected to Rotel sound processor using SPDIF optical motherboard asus sabertooth but i am getting 2 channel sound but using ps3 i get 5.1.
please tell me solution.
Answer #1
Answer #2
What model rotel are you using? What is the audio source? PC, HDTV, Cable, Satellite……?
Answer #3
Your suppose to get 5.1 only when playing 5.1 content and not at all times,Music for example is 2 channels (Stereo)
While some movies have 5.1 audio (more commonly denoted as AC3),However,Some receivers can convert stereo to 5.1 (Well,Not
entirely,It’d just clone the signal but it still counts for something),You should refer to the manual.
Answer #4
try googling “spdif surround sound windows 7” and see if any of those help