but you didn't include your your pc's make/model
I am wanting to connect my pc to my a/v receiver. I have a Yamaha 5.1 surround sound system and i want to connect it by either optical or coaxial (orange spot). Question is what sound card is decently priced and will do the job? coaxial is the best option for my as the rest of my optical spots are taken. Any help is greatly appreciated.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic