I just picked up an old Hohner B2A F1 to play around with… unfortunately it looks like a previous owner decided to play electrician and has done a bit of who knows what inside it. At the moment I get sound when I plug it in, I popped a new battery in and the active electronics seem to work as I get a nice boost when I flip the switch… But I know there are things still missing or broken. It has 3 knobs, I think they are two volumes and one tone but only the volume control toward the neck does anything the other knobs do absolutely nothing… I expect I will have to remove everything and rewire from scratch, but before I do that I have one glaring problem. The wiring diagram I found online that is supposed to be for a Hohner b2a is for a bass with 3 controls, 2 pickups and 1 output connection… The B2A that I have has 3 controls, 2 pickups 1 output connection and a hole where apparently another connection was supposed to be… I have no idea if it was a standard guitar jack or a XLR or what… I suspect it was for something as I can see some loose wires inside that I assume connected to whatever it was… I even have 2 screw holes near the larger hole that would appear to have been for holding whatever was supposed to be there in place. Does anyone have a B2A with this type of layout and if so what type of jack am I missing? And more importantly am I right to assume the control layout is supposed to be 2 volumes and 1 tone or is that incorrect? Trying to put this thing in working order but frankly at the moment I’m not sure what working order should be.