You have some choices. Is the receiver near your receiver? If so, and you have digital output from your PC sound card then connect through S/PDIF interface into a digital audio input. You could also use HDMI out from your computer if it's so equipped. A third option is to buy a Logitech Squeezebox or equivalent that will stream your digital collection to your receiver (Squeezebox also has a ton of online services like Slacker, Pandora, Mog, etc.).