Here is my current setup. Some cheap $20 soundblaster card that feeds into a Sony DE675 Reciever. Than into a set of Sennheiser HD 600's. I'm currently using a Midi to RCA adapter between the Soundcard and Reciever but would like to use the optical inputs of the reciever. Is there any internal/external sound card with optical outputs and would it make a big enough difference to warrant the upgrade? Thanks guys.