Please check AudioZeroClass::end(). Output to pin A0 seems to still be active after calling the end() method. I changed it to analogRead(A0) in my local copy and it seems to work much better. :-)
Thanks for the great work!
klw1971
--
void AudioZeroClass::end() {
tcDisable();
tcReset();
analogWrite(A0, 0); --->> Works much better with analogRead(A0) on a Feather M0
}