Two on/off switches on one pedal

[harshaw61]

I have a Fulltone ST-1 tremolo—

I'm hoping to convert the foot switch that controls half/full speed to a momentary switch for the whole unit, allowing me to apply sudden bursts of tremolo rather than turning the unit on and off with two clicks. (To be clear, I want both switches to function as on/off switches.)

I had thought this would simply be a matter of replacing the switch (with a momentary one) and wiring it with the on/off switch like a three-way light bulb switch in a house. But it turns out Fulltone uses 3PDT on/off switches that are fully wired (to capacitors? to prevent switch popping? that's my best guess). Does that mean this is impossible?

Any help is appreciated. Forgive my ignorance.

[mauman]

Welcome to the forum!

If you'll post a photo or schematic of the existing bypass foot switch, someone here can probably answer your question about it.

In the mean time, it's PROBABLY wired like one of these 3PDTs in the diagram below.  If so, you can add a momentary DPDT along with it as shown.  When the main 3PDT is in "bypass" the momentary DPDT will activate the circuit as long as you hold it down.   When the 3PDT is in "active" mode, the momentary switch has no function.  You can get an appropriate momentary DPDT at Small Bear and other places as well:  https://smallbear-electronics.mybigcommerce.com/dpdt-sf12020-m-momentary/

[Edit: on the momentary switch, the lower set of contacts are the ones that are normally closed (2-3 and 5-6.)  When you activate the switch, the upper set of contacts will be made momentarily (1-2 and 4-5.)