Ok, so... construct a daughter-board, containing the bluetooth module and a DA converter to output analogue speech to the empeg's Aux input.

Then either do the same for the Mic input - taking the analogue signal off the board, AD it and feed it to the bluetooth module. Or....

Hugo - How is the Mic sampled on the empeg board? does it have a dedicated chip, or is it the same one as the Aux? could a PCM stream be taken from the Mic sampler? - This would obviously not allow for any software tuning, but might be ok.

Oli.