Ok, I'm quite a n00b when it comes to audio and the like, but essentially what I'm trying to do is build a complete home a/v setup that my PC can also hook into.
I want to be able to take stereo or surround sound from my PC to an amp, and through an otherwise typical setup. I haven't yet bought any components, but am looking to buy a decent amp soon. Obviously I want to make sure I get an amp with the right connection types.
The mobo has "digital audio interface supports S/P DIF optical In / Out " - is this the best connection type to use? Does this mean I may as well just take the sound card out and use the on-board AC97 through this?
The opitcal is going to be the best connection you can get, however probably unecessary. I assume you just want to be able to plug your computer into your amp to play music and such. For this really you could just use a standard RCA connectors. You can get adapters to go from the little 1/8" jack to 2 RCA connectors. This is how I hooked mine up, I got the adapter from the local surplus store, for 0.95 cents.
Now I am not sure what you had in mind, but I sort of get the feeling you are trying to overcomplicate it.
Yeah, it's true that I'll mostly be using it just to play my mp3s through my home cinema setup initially! However, I may also want to play DVDs and other media from the PC, and so just wanted to know what type of connection would provide the best quality. If the optical is the best quality, then I'll be getting an amp with an optical in, naturally.
Well opitcal is a higher quality, the difference is measurable, not sure if it would really be audible though. Think of this way, most home A/V equipment is connected by RCA cables. So decide what the connection is worth to you, if you can get an amp with opitcal in reasonably, I'd say go for it, however, if there is a big price jump you may want to reconsider the RCA connection.