Here’s another design from Jon Patton. It’s a delay based on the popular PT2399, with an always-on preamp. The preamp is designed to have a flat EQ and won’t alter your tone. So the In and Out pads go to the input/output jacks, instead of the switch. You could still wiring this for true-bypass (just jumper the footswitch pads), but it’s designed to use a DPDT. Use one side to turn the delay on/off and the other for the LED indicator. Check out his build doc for a thorough and much better explanation of the circuit, a diagram for the footswitch wiring, as well as the schematic. In his layouts he has the Level and Tone controls as trimmers on the board. I chose to move these off-board, as it seems like useful controls to have externally.
