welcome to Apocalypse Audio, your haven for DIY guitar effects in the end times. so, start prayin to the fuzz gods, savin up those parts, and remember, when the big one goes off- keep your transistors shielded from those pesky electromagnetic pulses!

5.3.09

DIRTY BOOTS GERMANIUM OVERDRIVE

this little circuit is really what got me started in the whole DIY effects design process. i needed something that i could use to dirty up a loud, clean amp just enough to where it would have a touch of grit. it's a great little overdrive that can be used as a germanium booster as well as a fuzz if your pickups are hot enough.

it all started when i decided to breadboard the Trotsky Drive by Beavis Audio, which is basically a GE version of the Electra Distortion with a bias adjustment pot. using a russian GT313A transistor, i was fooling around with it, messing with values and such, when i remembered that the Bazz Fuss uses a diode in the C to B position instead of a resistor like the Trotsky/Electra. so i tried it out, and i got an excellently biased gain stage with just a bit of compression. then i realized that the circuit i was working on was PNP, where the BF is NPN. so the diode configuration is actually reversed. eventually i came to learn, with the help of many generous folks in the DIY community, that the GE diode that i was using was leaky, all of them are leaky, and it is this leakage that is actually acting as a large resistor and biasing the transistor. cool,huh? along with that, i'm sure that the diode is adding it's own little stamp on the situation with a bit of compression an break up.

after messing about with a ton of diodes this way and that, with filtering, in series, etc., i decided that i'm just not that big of a fan of diode clippers. i find them unnatural sounding, and their clipping just sound too "obvious" to me for some reason. so i ditched the clippers, added a small cap from C to B to roll off a bit of highs, and just put a whole nother stage in series with the first.

Lo! the Dirty Boots was born.

eventually i ended up trying a bias pot on the second stage and some different switching options for changing gain and tone, etc., but ended up with a normal emmitter controlled gain stage, a pregain control, and a volume pot. the latest mod was the series resistance between stages and ditching the cap from C to B on the second stage to open it up a bit.

it's really a great sounding little circuit using ge trannies which can be found on the bay for dirt cheap. the basic gain stage can be used for other things as well- it became the basis for The Toecutter.


give it a try sometime, or i'll send my band of mutated hobbit rat people to dig you out of your bomb shelter and eat you for second breakfast.

the thread at FSB about the Dirty Boots can be found HERE.

many thanks go out to Martin Chittum, Marcelo "Mac" Tripodi, and others that helped me understand along the way!

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here is a layout using common sized parts. i have another for use with the extra mojo axial caps and such that i will post later.

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daniel zink made this great version of the Dirty Boots in a Hammond 1590A box. a little killer!

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here's another one from mr. zink- very stylish!

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4 comments:

  1. I want that second one - It looks sweet!

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  2. i think it might be for sale, give dan a shout.

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  3. Have any audio samples for this... Please!

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  4. I'll try, but it'll just be on an iPhone. there might be some clips in the thread at FSB. I'll see if I can find them.

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