Hi, I need a sound card which will allow me to take an optical cable from my PS3 and play it through my surround sound speakers connected to my pc. My speakers are Logitech x540s, they connect with 3 3.5mm jacks, one for the center/sub, one for the front and one for the side speakers.
Well, any soundcard with an optical input has the ability to take audio from the optical input and output via the analog outputs.
The real problem comes with encoded audio the PS3 can put out (Dolby Digital 5.1 and DTS 5.1), which very few soundcards have native decoding support for. Getting standard 2.0 isn't a problem, but getting the 5.1 formats is.
The easiest solution would be a card that can handle the decoding of Dolby/DTS, but that limits you to the Auzentech Home Theatre HD, which is a bit overkill for this situation...The other option is a digital receiver, but again, thats mostly overkill if this is the only setup you would need one for.
The best bet may be to simply use the PS3's 2.0 PCM output over optical, then upmix the audio via Dolby Pro Logic to 5.1 to your X-540's. While not "authentic" 5.1, it should be good enough, and a lot cheaper to boot. If this is the way you want to go, the HT Omega Striker and the Asus D1/DX are the best all around bets.
Appendum: The Auzentech HTHD lacks a SPDIF input. You might be able to use its HDMI input for Audio/Video, the HDMI output for Video, and analog output for audio? I need to read up on exactly what the card can do, I/O wise...[I'm including it in my next build, when Sandy Bridge releases].
Check your motherboard. If you have SPDIF Out you may verywell have a SPDIF In header on the the motherboard so you'll just need to order the bracket adapter.
PS3 supports 5.1 over Optical (TSOLINK) and 7,1 over HDMI.