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Designing a fuzz....help anyone?


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Recently I got a Germanium tonebender clone from a dude on eBay. It was advertised as having a fuzzface mode. It's got three transistors and two knobs...I didn't trace the circuits so I don't know exactly how it's done, but I would guess the 'mode' switch either drastically cuts the gain or takes one of the transistors out of the circuit. Either way, both modes sound sweet and I'm a fuzz addict now fo sho.


I was actually going to build a tonebender until I came across this one, but I still want to build a fuzz. I have a bag of 30 J201 JFETs that I bought for cheap so I could build a minimal 3dB preamp for my guitar, but that only requires one JFET! So now I've been poking around looking for some inspiration on designing a circuit. I looked at various Fuzz Face variations and making a Jfet face but they apparently don't play well with jfets in the Q1 position(only Q2), so I had to scrap that idea.


I like Jfets because they have a high input impedance and they won't load other effects or my guitar down. I have lots of them so I'd like to try using only J201s. My question is, what makes a fuzz a fuzz and not just a high gain distortion pedal?


I saw a JFET Mu amp in a National Semiconductor application note, which made it into some guitar FX sites too like Geofex.


here: http://geofex.com/Article_Folders/foolwfets/foolwfets.htm


I'd like to use this circuit as a starting point to make a fuzz, but it says the Mu amp circuit, the last one on that page, has a gain of around 90. How much gain does it take to make a fuzz and not just an OD pedal? There isn't any feedback in this circuit so I couldn't increase gain by adjusting feedback...how would this be done?


Fuzz face gain seems to be pretty arbitrary and I'm not even trying to clone a FF, just using it as a sort of 'design guideline'. I am looking for a thick, ballsy fuzz that retains note definition, not like a Big Muff where it's a big smooth mess.


I hope this makes a little sense.

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