How to Clean Noisey Controls on Your Amplifier

This is a very common problem, not just in amps, but any eqipment using pots (potentiometers) and usually easily remedied.

The following description refers to a guitar amp but can be applied to almost any equipment.

First of all. CAUTION. Always work with the equipment switched off and unplugged from the wall socket.

Be aware that certain kinds of equipment work at high voltages that can kill, and these pieces of equipment can store a high voltage charge for a length of time.

Valve amplifiers and the older CRT televisions come in to this category.

If you do not feel competent or are unsure, leave it to a qualified technician.

Here is the procedure.

First of all make sure it is unplugged from the wall and has been for a period of time to allow it to discharge.

Remove the chassis by undoing the screws on the outer case, the chassis should then slide out backwards. Most amps slide out from the back though some amps slide out from the front so you will have to judge which way it wants to go.

Note which way the wires are attached to the speaker before you disconnect them, they must go back the same way.

Slide the chassis out being careful it doesn't drop or that you pull any wires off.

This is what the controls look like from the front of the amp.
This is what the controls look like from inside the amp.
This is what one of the controls looks like on it's own. Note the indentation on the top, with a small gap on each side. This indentation acts as the stop at each end when you turn the control. Otherwise the control would just keep turning.
Here you can see the space where the three connectors come out.
If you can get a small can of WD40 or similar, with one of those plastic straw nozzles fitted, you can spray some into where the three legs come out off. This is often difficult if the control is soldered into a circuit board so use the indentation at the top of the control, you can spray some in there too.
If you look at the controls on the inside that are giving the problem you will see that they have a round metal case with three legs coming out into the circuit board or maybe attached to wires. In this case they are fitted too close to the board and difficult to get into so spray into the gaps at each side of the indentation. Not too much, you don't want to soak the whole amp.
Angle the plastic tube to each side of the indentation to get better access into the gap with the spray. A short burst to the right.
A short burst to the left.
Turn the control all the way to one end then all the way to the other end.
Do this several times to spread the lubricant and clear the dust.

Put the chassis back in the amp, connect the speakers and give it a try. Hopefully this will have cured the crackling or at least greatly reduced it. If it so bad that this hasn't worked then I'm afraid you will have to have the controls changed by a qualified technician.