Just to add onto my problems, the circuit diagram is split into two due to space constraints. There are arrows on both labelled A and B to show where the diagrams connect to each other, but on the second diagram theres 2 more arrows at the top and bottom marked 9V and 0V (voltage) but no arrows on the first diagram for them to join with. Should they just be connected to the power supply?

Also, can you fix crackly pots without replacing them?

Thank you :)