Interactive 3PDT Footswitch

What is a 3PDT Footswitch and How Does It Work?

A 3PDT (Triple Pole Double Throw) footswitch works like three separate SPDT (Single Pole Double Throw) switches that operate together. It features nine lugs arranged in a 3x3 grid, with each vertical column functioning as an independent switch. The middle lugs in each column serve as the common connections, toggling between the top and bottom lugs. When you press the footswitch, all three switches flip simultaneously. This makes it ideal for guitar pedals, where one switch can route the input signal, another handles the output, and the third controls an LED indicator, all working in sync.

How to Wire a 3PDT Footswitch for True Bypass Switching

Our interactive app demonstrates a common way to wire a 3PDT footswitch for true bypass switching. In bypass mode, the guitar signal flows directly from the input (lug 2) to the output (lug 8) through a jumper wire connecting lug 3 to lug 9, bypassing the effect circuit for a clean, unaltered signal. The input of the circuit is grounded when bypassed, via a jumper wire connecting lug 1 to the ground at lug 5 through lug 6, which helps prevent signal bleed or unwanted noise. When engaged, the signal enters the circuit via lug 1, is processed by the effect, and exits through lug 7 before continuing to the output via lug 8. Additionally, when the pedal is engaged, the LED circuit is completed by connecting the cathode of the LED to ground at lug 4 through the ground connection at lug 5, causing the LED to light up and indicate that the effect is active.