The 1070 doesn't have a USB port (may be thinking of the RR2150). The 990 and RR2150 can be connected via a USB cable, at which point they become a giant USB sound card (the best explanation I've been able to come up with) that will work with PCM stereo sources (so no using it for playback of DD or DTS soundtracks via USB). All you need to do is hook it up, let the computer find it, and start playing music with the media player of your choice (WinAmp, iTunes, ...).