Can this be done?

[crawler486]

I would like to put 3 distortion pedals
in a single box.

Each has its own stomp switch.

If I switch on any one of them,
the other two remaining must be switched off.
So that I can turn on only one of them at a time.

Is there some kind of circuit that will accomplish this?
What type of stomp switch do I need?

Regards

[R.G.]

Yes it can be done.

Look at illustration 7 in http://geofex.com/Article_Folders/fxswitchr/fxswitchr.htm
for how to set up two to eight momentary footswitches so that only the most recently pushed one sets the output latch. The output latch then controls a DPDT relay as in http://geofex.com/FX_images/relays2.gif

With this setup, you use a momentary switch for the stomp switches, and get one and only one on with each stomp. String the effects in series and only one is "in" at any time.

Use EA2 relays by NEC, in the Mouser catalog for about $2.60 each.

[Peter Snowberg]

I would go a little different way and either use a 74LS273 in place of the 373 in R.G.'s design with a double one-shot (one for the hold input and one for the clear input of the 273), or I would use two 74HTC74s with the switches wired to the set and reset lines via diodes.

The first approach allows you to step on two buttons at the same time and have them both stay on. You could also step on all three at the same time.

I see it come down to using a harder to find LS273 along with a double one-shot, or using two super easy to find HTC74s, six diodes and three resistors. You might have to add one-shots or some basic signal conditioning to make the second circuit work flawlessly when you step on multiple buttons at once, but a 74LS14 would allow for six signal conditioners in the same package.

Once you add at least three one-shots to the second circuit, it should work exactly like the first one.