Layout is based on old incomplete "schematic" and way too much time staring at pics.
Switching has been described as follows: When Tremelo/Wah and Echo are on, the Tremelo is activated. When Tremelo/Wah and Whirlwind are on, and ECHO is off, the Wah is activated. Echo, Fuzz, Whirlwind have their own effect(?)
The original effect was onboard a Teisco-type guitar. To mimic the phase switch inverting one of the two single coil pickups, I laid out a buffered phase inverter. The input signal goes through a buffer and out to the effect. When the Phase switch is toggled, the signal is split and one side goes to a phase inverter which then connects back to the other signal. The summed signal then goes to the volume knob and output.
I also included a separate powerboard to filter the power and supply each switch with an on/off led.