Author Topic: 3PDT switch wiring for PNP fuzz face clone - which method is better?  (Read 3102 times)


Am working on a PNP version of a germanium fuzz face (w/Fuller's '69 mods).  Will be using a 3PDT stomp switch for true bypass with LED.

I've come across two variations of switch wiring, and I'm not clear which might be better.  Seeking your wisdom & recommendations.

1)  Tonepad's suggested wiring: (see "Offboard Wiring 5" page)

2)  FuzzCentral's suggested wiring:, similar to GGG's

Which one is more likely to work well for this project?

I noticed that the resistor values for the LED also vary -- 1K vs. 2.2K.  Specific value here isn't a big deal, right?  Just need some resistance to keep the LED from blowing up?  (I'm planning to use either a red or blue superbright...)  Higher value = dimmer light but less current draw, no?

Thanks in advance.
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sir ladderhole

Both of the layouts are pretty much the same thing, but I'd go with the FuzzCentral one if I were you. It seems easier to follow, as each section occupies its own column;  first column is input, second is output, and third is LED. As for the resistor, you might want to play around with different values to see wich one gives you the brightness you want. But you are correct about what the resistor does.

Edit: Whoops, just noticed the Tonepad one grounds the input when the effect is bypassed. Not really sure what this does, but the FuzzCentral layout should be fine for your pedal.
« Last Edit: May 24, 2007, 04:22:41 PM by sir ladderhole »


FF has an electrolyte cap at the input. That cap causes a pop when true-bypassed by 3PDT switch and connected back. So either use the wiring with the grounded input or the other one but then use pull-down resistror to drag the "pop" down the ground.
I don't believe anything i haven't measured with my RoHS friendly Chinese multimeter.


 By grounding the input in high gain devices(like a FF) you prevent possible oscillation and overheating. Not saying it will happen without it, but it can't happen with it. Unplug your guitar, but leave the FF(or other distortion/fuzz/overdrive/boost) and listen to the noise when the pedal tries to amplify nothing... now short the tip and sleeve,(or just plug in your guitar and turn volume all the way down - same thing) and listen as it shuts up...
 Technically, for that reason the grounded input is better.
I am not responsible for your imagination.