Devi Ever Ruiner

Another brutal fuzz machine from Devi, and sounds great on bass and guitar. Pretty straight forward design–two cascaded transistor amplifier stages with a pre-gain control (intensity) and standard volume control. Pots are board mounted and it shouldn't take all that long to throw together.

EarthQuaker Devices Erupter

Merry Fuzz Friday, everyone! Here's EQD's latest fuzz offering, the Erupter. Essentially it's a JFET buffer into a pickup sim (the transformer) into a Fuzz Face-esque circuit. The Bias control controls the amount of voltage going to Q3 and is a center detent pot (though a regular B10k pot will work just fine). This one might benefit by adding a volume control to the output. Should fit in a 1590B just fine. The 2N497 transistor might be hard to source, but other low gain transistors should work. Schematic can be found here.

SoulSonic FX Chalice

Here's an other heavy one. This one was designed by Martin (aka soulsonic) and is basically 3 transistor stages and a tone stack into a JFET gain recovery stage. The toggle switch selects between distortion and fuzz.

The tone in Distortion mode is a big heavy, "Doom-y" sort of thing with alot of sustain. In Fuzz mode, it's a fart-y ripping sawtooth fuzz that's good for single-note lines and possibly bass, but it can do chords without totally falling apart.

The Contour control adjusts from a dark, low-mid-heavy tone when counterclockwise, to a scooped tone when clockwise. Around 12 o'clock it has a bit of a mid-peak.

 Schematic and demo can be found here. I added a trimmer to bias Q4 (J201 or 2N5457 would be good subs). Should fit nicely in a 1590B.

Wampler Paisley Drive

Got a request for this one. Another take on the classic Tube Screamer built for Brad Paisley. The traditional input/output buffers have been swapped out for JFET-based buffers, and there are two toggles for Presence and EQ (mids). Should be able to squeeze it into a 1590B.

Green Citrus

Here's a cool DIY design of a Green (Mutamp) amp emulator. Four JFET stages with a 2-band EQ and a Boost control. Should be a nice easy fit in a 125B with the board mounted pots. Here's the schematic for reference. Sound demo here.

Basic Audio Zippy

The Zippy is a silicon fuzz designed to give that vintage brassy sound. I've laid it out for board mounted pots and it'll fit in a 1590B or a 125B with top mount jacks. In the words of John Lyons...

Early fuzz boxes were designed to emulate the sounds of the saxophone.
The Zippy will allow you to channel your inner Coltrane with very reedy fuzz tones. Saxy and sexy.
At lower settings a nice musical razor blade fuzz sizzle.
Turn it up and it becomes an increasingly sharper toothed saw blade fuzz. It snarls. It spits. It goes from fat and thick to thin and cutting without losing it's signature top end sizzle and low end rumble.
The body control (bass cut) makes it easy to dial in just the right amount of beef. Zipper fuzz tones bloom and softly decay.

MI Audio Boost 'n' Buff V1

The Boost 'n' Buff is a simple little booster that doubles as a buffer when it's turned off (so it's not a true bypass effect). You should be able to squeeze this one in a 1590A. The FSw pads are for the bypass footswitch. If you want to build the second version of the Boost 'n' Buff, add a B20k to the output as a volume control.