This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Friday, May 1, 2015

Jack Deville Vintage Two-Knob Fuzz

I've been wanting to do a Fuzz Face with on-board pots for a while, and when I stumbled across a schematic of Jack Deville's (Mr. Black) take on the classic circuit, things just fell into place. This uses NPN germanium transistors (though you could use silicons if you must), and I tried to leave plenty of room for them if you're using some of the big Russian germaniums easily available off eBay (GT404, MP38, etc). You could build a standard Fuzz Face on this board, just mind the component changes and replace the resistor from Fuzz 1 to ground with a jumper.


Update 5/4/15:

Verified this last night. Here's a pic of my build.


Used some Russian мп38 germanium transistors (Q1: 80 hfe Q2: 110 hfe) and a 7.5k resistor in place of the 10k trimmer (ran out of those). For the input cap I tried out a couple different values (47n, 100n, 220n...) but settled on 39n, as it seemed to give more clarity that higher values. Socket and experiment.

6 comments:

  1. Hello! :) I have a question PNP transistors are fed -9V, but the NPN transistors are fed with + 9V right?

    My question is if I make a PNP version, need to invest electrolytic capacitors backwards?

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  2. Yes, you'll need to reverse any polarized components (electro caps, diodes). The other option with PNP transistors is to flip them so voltage goes in from the emitter and the collector goes towards ground. That way you can run the circuit as a negative ground effect and won't have to flip the polarized parts.

    Good luck with your build. This is a great sounding fuzz.

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    Replies
    1. Hey David! So good to go through some of the comments at old layouts :) For negative ground, you advise on flipping the PNP transistors. Does this go for all the effects with PNPs troubling us with positive ground? But then, why bother with charge pumps or batteries or searching for NPNs? There seems to be a catch.

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    2. Flipping PNPs around for use in negative ground circuits doesn't always work. I think some circuits and/or transistors don't like doing this. Also using a charge pump allows you to be a circuit true to it's original specs. The Fuzz Face seems to be a circuit that's ok with flipping around PNPs though, so you're probably ok doing it here. But I would highly recommend socketing the transistors for experimentation purposes.

      Personally I prefer to stick with NPN transistors when doing a germanium build. Just keeps things simpler for me.

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  3. I never really found a fuzz face I liked that much, but decided to give this a shot. I built this a while back, then got it back our recently to install the right pot values. I also auditioned a few different MP38A's until I found a good pair. I really like this circuit a lot, definitely a keeper! Thanks for posting the layout!

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