Does anyone know whether my old Yamaha DSP-E800 can be used a standard stereo amp? I'd like to hook it up to my PC at work as I do lots of video editing, but I don't know how to wire the amp to let me do this...if it's at all possible.
If the PC has a digital out, then perfect. Connect this to a digital input on the Yamaha. (make sure the PC is operating in stereo, not 5.1 or anything).
If not, connect its line out (or headphone out, whatever it has) to an analogue stereo input. Your computer will definitely have one of these.
Connect your speakers to the Yamaha's surround L/R speaker terminals (as its fronts are unpowered, according to the picture I found) and run the Yamaha in 'all-channel stereo' mode.
Actually it wasn't the best advice I gave.
I didn't realise that the Yamaha had a 6-channel input. It does, so you'd be better off using this. Use the surround L/R channels of the 6-ch input, connect the speakers to the surround L/R terminals, and use direct mode (or some mode of a similar name, I'm not sure what Yamaha call it)