Yep, I should do that but maybe I'll ask Andre (Audiohwr) before. He is the designer / representative of the Piano2.1...

I checked on Torsten Jeakel's RPI DAC which uses the PCM5102 chip. It can be stacked into a double mono configuration. So maybe there is a possibility to do the same with the Piano2.1 but merely by reconfiguring the SW... (hopefully ;-) as there are already 2 chips on the board.

greets
rupert