# Pedal Build - Silicon Fuzz Face



## dcole (Oct 8, 2008)

Hello Everyone,

I recently ordered all the parts up and built a silicon Fuzz Face. I changed it up a little bit but left most of the circuit the same. Here are the pictures:


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## mhammer (Nov 30, 2007)

Congrats!

If I can make a suggestion you may enjoy, the ZVex Wooly Mammoth is essentially a Fuzz Face optimized for bass. One of the controls it has is a variable resistance between the emitter of Q2 and the base of Q1. As shown, it is 100k of fixed resistance. The control is an additional 500k pot in series with the existing 100k. Interacts with the gain/fuzz pot in interesting ways to yield different qualities of fuzz that are not the sort of thing you might get with a simple tonestack.

Worst-case scenario, you stick a 510k or 470k resistor in series with 100k, and use a 3-position (on-off-on) SPDT toggle to either bridge that added resistor, add a second 470k in parallel (for a total series+parallel resistance of around 330k) such that you have three settings of 100k, 330k, and 570k. IMHO, big payoff for minimal investment.


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## dcole (Oct 8, 2008)

I have a buddy that wants we to try make him a fuzz for his bass so I'll have to check that out.

Here's some more info on the decisions I made: I labeled the input pot "T" as it tightens up the sound of the fuzz. All the way clockwise, its fuzzy and has loads of bass. When turned the opposite way, the sound is tighter with less bass. Tones and tightens! The 2k pot on the emitter of Q2 was used to adjust the bias of the two transistors. I turned it until ~4.5V was achieved on the collector of Q2. I also have a 270pF cap across the base and collector of Q2 (not shown) for stability and it takes out some high end to make it less fizzy.

I am playing this through a "Marshall 18 Watt" derived amp I previously built from an old 1950's PA. It sounds awesome and I hope to try it out through a reissue Super Lead tomorrow. I am heading over to a buddies to try it out compared to his Joe Bonamassa Fuzz Face tomorrow. Hopefully I can convince him to set up a mike and do a few recordings.


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## fraser (Feb 24, 2007)

nice!
that pot at the input will also allow it to get along with a wah- so its a double bonus.
ive actually got a silicon fuzz face breadboarded up.
just dicking around with which trannies i prefer in it.
what did you use in that one?


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## dcole (Oct 8, 2008)

I used Fairchild's SS9014. I specifically used the SS9014A classification which says from the datasheet that the hfe will be in the 60-150 range. The datasheet states these are pre-amplifier, low level & low noise transistors. I don't know if these sound any better than 2N3904's as I didn't socket them, but I don't really care. It sounds awesome. I have all the parts to breadboard this again so I might try some tranny swaps as I bought 2N5088's for a Big Muff build as well.

mhammer, have you played with fuzz faces much? I was wondering if you have, where you like putting a trimmer for biasing up the circuit. Most schematics show in the collector but I chose the emitter as I decided to not put in a Fuzz pot.


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## fraser (Feb 24, 2007)

dcole said:


> I used Fairchild's SS9014. I specifically used the SS9014A classification which says from the datasheet that the hfe will be in the 60-150 range. The datasheet states these are pre-amplifier, low level & low noise transistors. I don't know if these sound any better than 2N3904's as I didn't socket them, but I don't really care. It sounds awesome. I have all the parts to breadboard this again so I might try some tranny swaps as I bought 2N5088's for a Big Muff build as well.


thanks for the reply.
i tried 5088s in mine and it was pretty hairy-
sounded good, but not like a fuzz face lol.
im swapping stuff in and out, thats why i asked.
im liking 2n2222a, 2n3904, some bc108-
its like im stuck in a 'its fun to dick around with stuff' vortex.
or something.:smile-new:


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## dcole (Oct 8, 2008)

That is one of the problems with these things eh? So few parts that a guy can change them to his hearts content. Don't go playing it through a different amp now though. You may find it sounds different and have to start the tuning process all over again!


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## fraser (Feb 24, 2007)

dcole said:


> That is one of the problems with these things eh? So few parts that a guy can change them to his hearts content. Don't go playing it through a different amp now though. You may find it sounds different and have to start the tuning process all over again!


lol-
thats the thing, every combination sounds different.
but i guess that tweakability is the whole point.
ive actually got 4 amps set up right now,
its fun to crank them all for my tests.
neighbour came over last night to see if id share whatever drugs im on.
true story.:congratulatory:


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## dcole (Oct 8, 2008)

I upgraded the graphics with some colored Sharpie markers:


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