Can anyone suggest anything? Cheap would be good otherwise I may as well upgrade the mobo to one with spdif on board..
askelon: What are you trying to do? AC3/DTS should automatically be decoded via your AMP - any optical output with any card should handle that with no problems. If your trying to get 5.1 with say a game then you'll need to get a sound card that supports Dolby Digital Live which encodes the signal to AC3 on the fly - from memory only very certain sound cards support it - the creative labs ones should and a few select cmedia chipsets.