Viper probs, info moved from Schematics section

[MarshallJMP]

You can also make a footswitch without the leds then you only need 4 resistors, 4 buttons and a stereo jack. Downside is you don't know the status since you have no leds to show you.

[guitardude57]

Nope...won't work.  This is a logic based foot switch...powered from the amp, though the TRS.
Put a set of switches not sending high and low info, will fry the amp decoder...

[MarshallJMP]

The logic and the opamps are only for driving the led's, the rest is actually analog. It doesn't send out some pulses but 4 different voltages. Nothing will get fried.