Fairfield Circuitry Either/Or

The Either/Or is an expression toggle from Fairfield Circuitry, a Quebec-based pedal maker. Where an expression pedal sweeps a parameter continuously with a rocker, the Either/Or does something simpler: it toggles a single potentiometer in or out of a circuit, so a parameter jumps between two states rather than sliding between them¹.

What it does

Fairfield Circuitry describes the unit plainly: "Simply toggles on or off a 50k potentiometer"¹. In practice that means the Either/Or sits where an expression pedal would, but instead of a smooth sweep it gives you two positions. Press the switch and the connected parameter snaps to one value; release or press again, depending on the mode, and it snaps back.

The switch runs in either momentary or latching mode, written by the maker as "(M)omentary or (L)atching"¹. Momentary mode holds the alternate state only while the switch is pressed, which suits effects you want to duck in and out, such as kicking a filter or a pitch setting on for a bar. Latching mode leaves the state engaged until you press again, which suits toggling a setting between sections of a song.

Because it works through a potentiometer rather than a dedicated control protocol, it is aimed at gear that accepts a 50k expression or control input. Players looking for continuous heel-to-toe sweeping rather than a two-state jump would use a conventional expression pedal instead; the Either/Or covers the on/off case¹.

Questions