Valve Wizard Engineer's Thumb

A little blog update: You may have noticed there wasn't a post yesterday and that there is one today. Why on a Tuesday and not a Monday? Some big-ish changes are coming to the site in the near future, which (along with a bunch of other small things) is taking up a lot of my free time. So don't freak out. I'm still here. Layouts are still coming. Just not quite as frequently (2 a week instead of 3). Now that that's out of the way...

Here's the 5-knob version of the Engineer's Thumb compressor. Been meaning to do this one for a while and decided to do it in Eagle. It's generally considered a Dyna-Comp/Ross Comp killer, and uses one side of an LM13700 chip in place of the old CA3080. This one will fit in a 125B with all 5 pots board mounted. The Bright switch is off board, but that's just 2 wires. If you don't feel like etching, you can get a board fabricated off OshPark. Original info on the circuit by the designer can be found here.

Build doc here with schematic, BOM, and drilling template.

Death by Audio Kill Kill Filter

It's a Fuzz and Filter Friday! Here's DBA's Kill Kill Filter. At it's heart is a stripped down Big Muff (only one distortion section without clipping diodes) with a footswitch selecting 2 different pots in the tone stack. Schematic can be found over on FSB.

Colorsound Tremolo

Haven't done a tremolo in a while, so let's remedy that with the original 4-transistor Colorsound Tremolo (the re-issue is the 3-transistor version). Originals used 2SC945 transistors (BCE pinout), but I've laid this out for more common NPN transistors with CBE pinout. You might want to use a C100k pot for the Speed control. Here's the schematic for reference.

Friedman BE-OD

By popular demand, here's the BE-OD from Friedman, one of the best Plexi in a box pedals around. Well, not Plexi really. It's designed to emulate the Friedman Brown Eye tube amp head. Laid this one out for board mounted pots, and it will fit easily in a 1590BB. More info can be found on the FSB thread for this one.

Field Effects Acceleron Fuzz

Here's a pretty unique fuzz for Fuzz Friday–the Acceleron from Field Effects. It uses a mix of BJT and JFET transistors and offers a wide range of fuzz tones. I've laid it out for board mounted pots and you'll notice a big box film cap labeled ??? It's probably 2.2µF, but socket and experiment.

Throbak Overdrive Boost

Pretty much a Colorsound Overdriver clone. Laid this out for a 125B (because of the dual footswitches) with board mounted pots. The boost footswitch bypasses the PreGain pot and only uses one side of a DPDT. Use the other side for LED wiring. If the off board wiring is confusing, check out the thread with the schematic here on FSB. The diagram is for a vero layout but the wiring is the same.

JHS Charlie Brown V3

Unrelated to the Angry Charlie circuit, the Charlie Brown emulates the brown sound of a JTM45 amp and is a variation on the zVex Box of Rock without the boost section. The input stage is an AMZ Mosfet Booster (replacing the SHO input stage of the Box of Rock to avoid crackle in the gain pot), and the tone control has been modified to include the AMZ presence control.