3PDT

3PDT is a three-pole, double-throw footswitch commonly used as the bypass switch in effects pedals¹. It enables true bypass switching, and its three poles allow the switch to also control a status LED alongside the bypass function¹. Many pedals use 3PDT true-bypass switches, often paired with Switchcraft jacks²³⁴. Builders describe 3PDT switching circuits as sonically transparent, preserving tone⁵. The switch can be replaced by relay-based bypass systems intended to be more reliable and silent⁶, or by switch replacements that do not alter the pedal's sound⁷.