Pot Swap Board

[fluffhead]

I was thinking about ordering one of these pot swap boards from fuzz dog parts (https://shop.pedalparts.co.uk/Pot_Swap/p847124_12489372.aspx), when I thought hey, thats something I could easily perfboard together with my limited knowledge of electronics. It'd be cool to throw some sockets in and quickly switch two pots, trimpots, transistors, fets, whatever. The one thing I don't understand is why on the schematic/board the #1 pot pad connection isn't on the switch. Is it because one lug of a pot is usually to ground? Or does it just not matter if one lug is still connected if the other two aren't? I ultimately wanted to try to use it to switch between a mosfet and a transistor, with a bicolor led showing which one is being used. In this situation, the emitter/source would be going to ground so I guess it wouldn't matter? I just don't get why every other lug/leg/lead would be on the switch but not one. I'm sure this is a dumb question, but again, limited electronics knowledge.

[bluebunny]

It's nothing to do with "usually ground".  It works because one or other of the pots is not in circuit.  Remember, electrons only flow in a circuit.  So the unswitched pot is a dead-end, therefore it's simply not there.  Same applies if you wanted to switch two transistors.

[fluffhead]

Thank you! Absolutely makes sense. Now I feel dumb...er than usual.

[Ben N]

I like this. I would love to see an electronic version, to switch two pots, that works with an SPST momentary.

[ElectricDruid]

I like this. I would love to see an electronic version, to switch two pots, that works with an SPST momentary.

4053 CMOS switch IC is your friend. That'd do the job. Tie the control inputs together so all the switches change together. Then use a pulldown resistor and the SPST momentary up to 9V to create your control signal.