potentiometer

A potentiometer is a variable resistor, a resistor that turns so a user can manually modify a value in a circuit.¹² It contains a resistive track and a movable contact called a wiper, and it has three lugs named A, B and C, or 1, 2 and 3.³⁴ Its resistance variation can be linear or logarithmic, also called audio; the prefix A indicates audio or logarithmic taper, B linear, and C inverted logarithmic.⁴ In effects circuits, a potentiometer wired as a variable resistor to ground at the end of the circuit just before the output acts as the simplest possible volume control, reducing signal amplitude to set output volume.¹⁵ Placed in the loop of an operational amplifier, it lets the gain vary by turning it, which suits a volume boost or setting the maximum gain with clipping diodes.¹