Amp is a great looking product - I will need to order one soon!
I see that it is a 'fully digital' audio path, however, is it possible to have an analogue input to the Amp, so that you could have an external audio source from an mp3 player (for example). I would then look at using the GPIO pins to switch between RPi audio, or external audio source.
Hope this is possible, Thanks for your help (in advance!)
External Analogue Input