David Martin wrote:And now... The result!
Instead of cutting the leg on the pot, I removed the track joining the leg back to the wiper, and added the wire as shown. And... The bass control, far from exhibiting the classic top boost feature, didn't work at all... It did nothing.
David - simply cutting the track between the wiper and the end lug will NOT work!!!
The reason is that the order of the circuit as laid out on the PCB is: wiper > pot bottom lug > 10k > ground.
Thus just cutting the wiper > pot lug connection will only leave the wiper "hanging in the air", and the control will do nothing, as you found.
The fix it to disconnect the pot bottom lug from the wiper (without disconnecting the wiper from the 10k resistor) and then connect the pot bottom lug to GND.
In praxis the solution suggested in the previous picture is probably the easy/best solution, and it WILL put the circuit back to the original TB design. Make sure when the pot lug is cut that it is fully isolated from the remains of the lug sitting on the PCB. Either insert a piece of isolation tape, or better - unsolder the cut off pot lug end from the PCB trace (making sure the wiper doesn't get unsoldered in the process).
Erik
Look forward to your findings