I got the idea that they just fed analogue out from the RR/Xbox-analogue/Slimp3 directly to the amp, but when testing the Xbox-optical used the optical input on the amp (ie, used the amps DACs).

Given the cost of the amp (well, the entire setup really) it says good things about the Receiver's DACs that people preferred them to whatever you get in a meridian 7.1 amp!

The central's audio output uses the same DAC as the receiver, but the circuitry was redone and gives even cleaner output.

Hugo