This is the development board I'm using for the soundchip coding and testing.
I just added PWM- and noise-channels.
Running the Atmega328 at 16MHz@3.3V, which is slightly under-volted seems to work well. The MicroPython-board uses 3.3V, and I really would rather skip the voltage conversion if I can.
2 "speakers" because the sound is full stereo :D