trim pot

A trim pot, or trimpot, is a small potentiometer mounted inside a pedal, usually adjusted with a screwdriver, that sets an internal parameter not assigned to an external knob¹. Sources describe trim pots controlling functions such as bias in fuzz circuits²³⁴, boost gain range⁵, low cut⁶⁷, hi-cut⁸⁹, input gain¹⁰, feedback¹¹, envelope sensitivity¹², level to prevent volume loss at deeper tremolo depth¹³, H-Mids center frequency¹⁴, gain matching¹⁵, and hidden distortion or presence¹⁶¹⁷¹.