Vsex Tool - Zvex Machine

I've had a few emails requesting this scheme so here it is for you all to view :-)



Here's a demo video here:

And a short description from the Zvex Website:

"I designed this new distortion generator, Machine, with some different limitations. Like try playing chords through it. Hmmm. But put it in front of any string of fuzz pedals, and try to make it disappear. Machine is actually a dual frequency-tripler circuit that uses crossover distortion for the first time in any pedal, ever. It generates the distortion of the wave in the sloped part of the cycle, instead of the peaks and valleys like all other distorters and fuzzes. In other words, it distorts when your guitar string is in the middle of vibrating, while it's swinging, not as it's turning around. That's the same place where your speaker cone is sort of coasting, between all the way in and all the way out. Where nothing is happening, this pedal happens. With Machine you can leave your favorite distorting pedals on and still add a new element of energetic grind."

It's using frequency triplers like Tim Escobedo's "Tripple Fuzz", they sound pretty cool (The Lovepedal Karl also uses this circuit structure):

Skreddy Mayo - Super Big Muff

[This post also includes info on how to build up a Skreddy Pink Flesh work-a-like]

Here is the schematic of the great Skreddy Mayo - a superb modification of the old Electro Harmonix Big Muff. The tone is supposed to be a match for the classic Big Muff Tone from The Smashing Pumpkins "Siamese Dream" album (The name of the pedal harks back to one of the song titles "Mayonnaise"). Now Marc swears by building these with the exact part type specified so if you want the sound - get the right parts. I built one up on breadboard and it was one of the best muff variations that I have played!
As you can see the scheme is drawn by Marc himself, thanks for that Marc, great stuff!

Now the Skreddy Pink Flesh - Marc himself posts that the mods you need to make to the Mayo circuit (apart from transistor selection!) would be:

C1 – 10u
C8 – 4.7n
Cx – 220-470p
C3 – 68n

Mid Boost: Switch in 4.7n parallel to C9
Add a 100R resistor after Dx

Here's a vero layout for it (Drawn by IvIark - http://www.tagboardeffects.blogspot.com, his site is great and has vero board layouts for just about everything!):

And finally a demo video: 

Xotic RC/AC Booster Overdrive

The Xotic AC Booster a well loved booster/overdrive pedal, this demo shows why -

And here's a scheme for you:


You can clearly see it is a traditional style opamp based clipper. With one interesting addtion, it has an active tone stack present after the clipping section! Here's some more info, available on the Xotic site: http://www.xotic.us/effects/ac_booster/

Kusi of the freestompboxes.org forum contributed these mods to change the xotic AC booster into the xotic RC Booster:
C1 = 47nF
C2 = 1uF / NP
R8 = remove and bridge
C4 = remove
R5 = 22k
R7 = 250k
Clipping-Diodes = 3x 1N4148 each side