It's just a bypass switch. That's it. My version of the Demedash Incandenza clickless relay stomp.

 This is another layout that I posted over at Dirtbox but it is most definitely the thing I build+use more than anything else I make. It's a version of the Demedash Effects Incandenza relay bypass on/off switch that Steve Demedash came up with a few years ago.

No microcontroller required, super-low parts count, and absolutely no mistriggering. My stripboard drawing has pads marked for all four leads that come out of your standard true-bypass circuit: send, return, +9v, ground. So you can just slap this on to any circuit that you desire, that uses a true-bypass switch. Polarity protection is included on the switch daughterboard so you can omit that from the main circuit, too.

The relay is 5 volts, dual pole/dual throw, and non-latching. There are a couple other versions of this schematic floating around out there but this contains one pretty important edit from Steve Demedash himself: the 100 ohm resistor that is placed between the 555 chip and the relay itself. This limits the juice that the relay receives, as the chip puts out about 8v and the relay is rated to 5v. I've listed three different model relays on the drawing itself (and I may have mentioned a 4th - the Panasonic one - on the schematic), but just about any relay of the same size can be subbed provided you check the pin out and datasheet. All of the relays I have listed have a coil impedance of about 175-180 ohms. If the relay you want to use has a higher or lower value, you may need to raise or lower the value of the 100 ohm resistor on the layout, too.

I realize that building an entirely separate board for the on/off switch is something that a lot of folks may not want to do. But if you ALL READY like giving yourself a hard time by working on strip/vero, why not go the extra mile for a switch that is much more reliable than a mechanical 3PDT?