True bypassing a DOD pedal.

[Rick C]

Has anyone ever done this? I have an Envelope Filter I'd like to try it on.

[Mark Hammer]

There are two ways of doing this.  One is to bypass the buffer circuitry and switching FETs so that they are never in the signal path (i.e., the stompswitch does the switching, not the FETs).  The other way is to leave the pedal "on", and bypass the entire circuit, buffers and all.  That can be done via a rehousing, but it can also be done via a simple loop-selector box, without changing the DOD pedal at all.

Can I ask why you want to use TB?  That will help to determine what sort of solution will best accomplish what you want.

[Transmogrifox]

There's enough space in there to do it.  You can even adapt the flip-flop & momentary to drive a relay.  Check out my relay driver circuit:

www.geocities.com/transmogrifox/relay

You would want to hardwire the gates of the switching FETs so that the pedal is always "on", then use the input/output leads from the audio jacks for your send/return connections.

The first PDF has a circuit for doing it with a CD4049 (bottom half of the page). You could epoxy the CD4049 to the top of the relay, twist the unused pins in the configuration shown in the schematic, and clip the ends.  Solder wire to the pins you'll use, and maybe glue the resistor onto one side of the relay, capacitor to the other, and you'd have a pretty compact package for bypassing.

If you solder wires for leads to each of the relay pins, and everything external you need, you could then completely pot the aparatus in epoxy and wouldn't have to worry about stuff wiggling apart or making contact with conductive surfaces inside the pedal.

An even more compact and friendly way to do this is with an 8-pin microcontroller.  Follow the link to the second PDF for a schematic, though you do need to program the microcontroller chip.  I am currently selling pre-programmed chips for this purpose at $5/ea.

[Rick C]

Can I ask why you want to use TB?  That will help to determine what sort of solution will best accomplish what you want.

It's a bit of a tone killer and there's a little high pitch noise when it's off.