Another name for variable attenuator, volume control, or potentiometer (see WFTD archive Potentiometer). A fader works just like a standard potentiometer, only instead of rotating, it slides along a straight path. Faders are most commonly used on mixing boards and graphic equalizers, where it is nice to have both an easy way to move the level up and down, and to provide a sort of graphic representation of the relative levels of many channels (or frequencies in the case of an EQ). Faders have also historically been used on some synthesizers as controllers for various parameters. The name comes from the phrase “fade out.” Once faders came into existence it became much easier for an engineer to do a smooth fade out.