I just picked up an old Fatar (Studiologic SL880) midi controller. It has a really nice weighted action and all the keys are working great.
The one problem I've encountered so far is that it continously / randomly puts out Control Change 007 Main Volume midi messages. I've 'fixed' this by plugging in a sustain pedal into the volume pedal socket, which stops any Main Volume messages being fired.
Looking inside there is a single main board. I wondered if I should try replacing the volume socket, or other components in the vicinity? I wondered if anyone who had implemented a circuit for volume control would know what the circuit would look like. I don't have a schematic for the board.
An alternative would be to fake the equivalent of a sustain pedal - it seems like a bare jack plugged into the volume socket by itself doesn't stop the Main Volume midi messages. Any idea what I should add to the bare plug to make it behave like an unpressed sustain pedal? br> br>