I was thinking of using the USb to connect ot my MAC mini. Does the usb cord give you surround sound output from your PC or is it just stereo? Any idea if it would from the MACmini? How does it install?

I'm trying to figure a way to ouptu dolby or DTS from the mac mini. There are some USB audio deviecs I've found that have optical, but no surround capabilty. I wonder if USB is the answeR??!?