There are many applications for potentiometers, including volume and tone control in audio equipment, brightness and contrast control in televisions and monitors, and position sensing in linear actuators and robotics. In addition, potensiometers can be used as sensors in a wide variety of applications, including automotive systems, HVAC systems, and manufacturing processes. However, this time i would like to talk about mechanical potentiometer on some vintage audio equipments.

These mechanical potentiometer components, like any old equipment, need a cleaning ritual, and they do so in the same way that a piece of electronics needs a tune up. Over time, volume knobs on a receiver or a fader on a mixer, overtime they get crackly, scratchy and generally scruple due to the oxidation and gunk that accumulates inside them.

Oscilloscope trace of a potentiometer caked with gunks.

[Keith Murray] talks about some ways in which slider-style potentiometers can be cleaned, and how well each cleaning method works by testing the smoothness of the transition over time with an oscilloscope.

In the end, the only options to bring the performance back to this old potentiometer is a soak in isopropyl alcohol, and a full disassembly followed by manual cleaning. Also, it's an acceptable tradeoff to use contact cleaner and using the compressed air to blast the fader potentiometer to avoid disassembly, however.

1/3-octave graphic EQ sliders potentiometers after cleaning