What the Wah?

Hadn't done a wah in a while and thought I'd do project where you can build several old school wah circuits on the same board. Many of the early wahs back in the late 60s were based on the original Thomas Organ CryBaby, and as a result many of them follow the same topology with a few value changes. Here's the schematic:

A lot of the original transistors used have a BCE pinout, so I've made 2 layouts: one for BCE and one for the more common CBE pinouts. Generally speaking your just need transistors in the 300-400 hFE range, however with many circuits, different transistors offer different flavors. So as always, socket and experiment.

What the Wah? Project

One-Knobber Project

I haven't made a detailed project in a while, so for Fuzz Friday here's the One-Knobber. It's based on the old Dr. Tony Balls stripboard layout that covered the ColorSound One-Knob, D*A*M Meathead and Dark Meathead, and a one-knob adaptation of the '66 Vox ToneBender, and I've added the Ritual fuzz by Black Arts Toneworks.

Project PDF

ProCo RAT Project

Here's the classic RAT distortion with on-board pots. All the ProCo RATs are essentially the same circuit, just with a few value changes over the years. For this project, the board can be used to make 4 different versions of this great distortion box: The original RAT, the RAT 2, the Turbo RAT, and the You Dirty RAT. Here's the basic schematic:

The component names from the above schematic follow those in the layout drawing below.

The project file with a full BOM, scaled transfer images, and drilling template can be found here.

Thanks to Cody for verifying this ahead of time for me. You sir, are a scholar and a gentleman.

The Drivestortion Project

I really enjoyed making the Big Muff Project file a couple months ago and thought it would be fun to make a similar project based on the MXR Distortion +/DOD OD250 circuit (in an attempt to combine the 2 names I call this project the Drivestortion). This circuit was also cloned by other pedal manufacturers (apparently this was the Timmy of the 70s), so the project provides component values for a couple of these as well. Let's start with the schematic:

This is the basic circuit for several versions of the DOD OD250, the MXR Distortion +, the Ross Distortion, and the DeArmond Square Wave, just to name a few. The only difference between all these is differing component values (and sometimes not even that). The component names from the above schematic follow those in the layout drawing below.

For a full BOM for 6 different versions of this circuit, download the linked file below. In addition to the BOM, it contains scaled transfers for etching your own circuit board and a scaled drilling template for building the effect into a Hammond 1590B enclosure.

Effects Layouts' Drivestortion Project

Electro-Harmonix Big Muff π

I got a request for a layout of the Big Muff that could be used to build the Triangle, Rams Head, Green Russian, or NYC versions. While it shouldn't be that hard to take one of my previous layouts of the BMP and make the value changes, I thought I'd make a more detailed project than I normally do. First, let's start with the schematic. This is the basic circuit used by pretty much every variation of the Big Muff (excluding the IC Big Muff):

The only difference between versions is a handful of component values. Generally, the circuit was tweaked to work with whatever Mike Matthews had on hand. As a result, there are about 18 different variations produced by Electro-Harmonix. Now, not all of those variations sound all that good. But over the years several really good sounding Muffs have been traced and their component values posted on the web (mostly on Kit Rae's awesome Big Muff site). The 4 versions specified in this project seem to be some of the most popular and best sounding Muffs.

The component names in the schematic above correlate to this layout:

For a full BOM for all 4 versions, download the file linked below. In addition to the BOM, it contains scaled transfers for etching your own circuit board, as well as a scaled drilling template for building the effect into a Hammond 1590B enclosure.

Effects Layouts' BIG MUFF Project

If a BMP variation you want to build isn't specified in this project, use the above schematic and compare it to the schematic of your desired version to figure out what components go where.

Updated Sept. 2, 2015 to correct schematic, placement of Tone pot, and drilling template.