I haven't looked into that yet. I've looked over a few tuts using the 328p but not much else. I have plenty of those on hand so that'll be my next test.I hesitate to mention this but have you looked at the PJRC teensy and their audio board? Very sophisticated transforms can be done easily with their audio library. They have a very nice tutorial. Not dirt cheap but around $35 for both a teensy 3.2 and the audio board.