Silly question but I was wondering if it's possible to rout the a8 -> external Dac -> a8 XLR Input -> power AMP. So basically using the a8 as a streamer to stream to an external dac, take the signal from the external dac and input it back into the a8 and use the a8 as a pre-amp.
Since you cannot have both a digital (towards the external DAC) AND an analog (towards your amp) output active at the same time, it's a no. The machine is a streamer, not a mixer.
You also can't have two different inputs (the internal player and the xlr or rca in) active at the same time on your A8. You need a separate preamplifier for that.
