Attached to each amplifier is a little trimpot for adjusting the chord/keyboard volumes. On most Optigans, these trimpots can be accessed by the little holes on the back of the unit. If you still can’
When I play the top most key on my Optigan, I hear one of the chord tracks bleeding through. What’s wrong?
Crosstalk! Learn to live with it! If you don’t have the test discs, the easiest way to hear the crosstalk is by pressing the top most key on the keyboard. Crosstalk changes with the weather, basically
Optigan Audio-Output Mod
Here’s a freebie from the Service Manual – it’s instructions on how to modify the outputs on your Optigan to be more suitable for recording and amplifying. Optigan Audio-Output Mod [pdf]