How to Replace the Volume Control Knob Preamp
- 1). Measure the diameter of the metal post protruding from the volume control. The diameter of the post usually is 1/4 inch. This is the measurement needed for a replacement knob.
- 2). Turn off power to the preamp, and unplug the electrical cord.
- 3). Line up the hole on the underside of the replacement knob with the shape of the metal post on the volume control of the preamp. The post typically is round on one side, like a half-moon, with a flat edge.
- 4). Slip the replacement knob onto the post. Push firmly until it seats and will not go on any farther.