Flying Guillotine Fuzz

For #fuzzfriday I present to you the Flying Guillotine Fuzz, designed by Freppo over on FSB. Here's what he had to say about it on his blog:

The front end, tonestack and the output stage are all borrowed from the Big Muff, but the two Muff gainstages is replaced with a discrete op amp (by Joe Davission) modified with a odd feedback transistor clipping configuration. It's a VERY loud circuit. Way louder then the loudest Big Muff I've built.

Guitar Direct Box

Got a request for an active DI, which coincided with a project I'm working on, so it seemed like a good idea. This one's designed by Samuel Groner and modified by Jack Orman. The schematic came from his blog and can be found here, along with some other info about the circuit.

Golden Dragon Overdrive

Here's a simple overdrive circuit adapted from the National Semiconductor "Ultra High Gain Audio Amplifier" and Jack Orman's "Minibooster" by Andrew Carrell (Dragonfly). It should easily fit in a 1590a.

Bearhug FET Compressor

Here's a simple compressor design by Jon Patton (aka midwayfair) that's good for guitar and bass. In Jon's words:

The Bearhug is a tonally transparent, ultra-quiet, tiny, and easy-to-build compressor. It occupies some middle ground between the ultra-subtle compressors like the Flatline/Afterlife and Orange Squeezer and the super squishy compressors like the Ross.

For more info on the design, Jon goes into detail in this thread on DIYSB.

I built this one last night and it's everything Jon says it is. Very subtle, and a little bit of volume boost if you want it. Here's a few pics of my build.

Tres Hombres

The Tres Hombres is a distortion/fuzz designed by Marcelo Trípodi on the DIYStompboxes forum. In a nut shell, it's three similar germanium transistor stages with fuzz and volume controls. There's also a switch to add an extra capacitor at the input to fatten up the sound. Marcelo recommends 2SA101 transistors with an hFE of 50 and leakage of 150ua. Socket and experiment. The perf side of the layout below is for positive ground, and the PCB is for negative ground.

Kay F-1 Fuzz Tone

Here's the layout for #fuzzfriday! The F-1 Fuzz Tone is one of Kay's budget effects from the 60s housed in a plastic treadle pedal. Essentially it's the poor man's Univox Super Fuzz. The treadle would control the Tone pot, with the overall level of the effect fixed at max. This isn't that big of an issue as output is around unity. The circuit can also produce an octave effect as well. Originals used BCE pinout transistors, but the layout below reflects the more common CBE pinout. Originals also used germanium diodes, but silicon can also be used.

Mods:
If you want to add a volume control, start with a 100k pot (other values may work better, that's just what I'd try first), connect lug 3 to the Out pad on the board, lug 2 becomes Out, and ground lug 1. It may also be useful to add a pre-gain pot at input. Again start with a 100k pot, lug 3 becomes the new In, lug 2 goes to In pad on the board, and connect lug 1 to ground via a low value resistors (470Ω, 1k, etc). No idea how useful these mods would be, just a few basic things that came to mind as I laid it out. If you're adding a Volume control, it might not be a bad idea to put a booster (LPB-1 would work well) between Tone 2 and Volume 3. YMMV

DOD FX25 Envelope Filter

The FX25 was initially produced by DOD in the early 80s and is an OTA-based envelope filter/auto-wah. It's a fairly tweakable and you can find various mods on other sites, but this is for the stock layout. The original switching circuitry has been removed, so you can use true-bypass. An LM1458 is listed in the layout below, but just about any dual op-amp should work there (TL072, NE5532, JRC4558, etc.), so if you get a little distortion, try a different op-amp.

Update Aug. 10, 2016:

I've fixed the layout as per NapAlpha and Eduardo's comments below. Thanks for catching that guys. Sorry it took me so long to make the fix.