Here is an example of a setup we use in-house:
1. Creative USB Sound Blaster X-Fi with 5.1 Surround. You will need 1 x RCA to RCA cable and 2 x 3.5mm to RCA cables
2. Sabrent SBT-USC6K USB to Serial Converter
3. USB Extender over CAT5 (either a Gigaware extender from Radio Shack or Cables-To-Go USB Super Booster Extender)
Setup
1. Connect the USB extender to your PC that is running CasaTunes and connect this to your CAT5 cable you have running to your Russound and connect the other end of the USB extender to the CAT5 there.
2. Connect the powered USB Hub to the extender by the Russound.
3. Connect the external Sound Blaster X-Fi card to the USB Hub
4. If Vista and Windows 7 do not recognize the X-Fi USB Sound Card you will have to load the included drivers on the PC. Make sure the card is set-up as a 5.1 soundcard in the sound manager.
5. Now you will have up to 3 PC sources of music for your Russound. Just hook up the required cables to the sources on your Russound.
6. Connect the USB to Serial adapter to the USB hub and the serial interface on the Russound
7. Configure CasaTunes Setup to use the appropriate COM Port and Sound Card
Note: Instead of the USB-To-Serial Hub you could use the Moxy Serial Server above.