Old secret 2OPFM
2OPFM is a digital 2-operator FM voice in 6HP. It features 2 sine wave oscillators and a decay envelope to control their amplitudes. Perfect for growling percussion and plucky melodies.
Note: -12V was left unmarked on the power header on these modules (who would do such a thing?!) The red stripe on your power cable should go DOWN. -12V is DOWN.