The SynQuaNon Single Distortion Switch is an integral part of the pickup line. All pickups (Mono Distortion, Mono Distortion with Hex Clean Output, and Mono Distortion with Hex Distortion Output) have dual distortion gain stages built in, with distortion levels determined by control voltages applied through the rear GAIN1 and GAIN2 connectors.

The control voltages for GAIN1 and GAIN2 may be generated as follows:
Two Single CV Distortion Potentiometers
One Dual CV Distortion Potentiometer
One Single CV Distortion Potentiometer and one Single Distortion Switch
Two Single Distortion Switches
 
Instead of having a continuously variable control voltage for either GAIN1 and/or GAIN2, one can use the Single Distortion Switch to create two distortion level presets. Each position of the switch engages a separate trimpot on the back of the PCB. Adjust a desired distortion level on each one which can then be activated repeatedly and accurately by toggling the switch.

Combine the switch with a Single CV Distortion Potentiometer on the other pickup gain stage for variable control.