This Xitel Pro HiFi-Link is very good to transfer audio files via a digital connection (either Toslink or Digital Coaxial) from a PC to a receiver or other component with a Digital input.
http://www.xitel.com/product_phfl.htm
it's about $78 at buy.com
http://www.xitel.com/product_phfl.htm
it's about $78 at buy.com