Chuck D. Bones
Circuit Wizard
Seems like everyone offers boards for this vintage box of nasty. Truly an unruly fuzz, it's best for single notes, even with the Octave turned off. Aion added two mods to this board set: a 3rd position on the OCTAVE switch that bypasses the Octave diodes completely and a 3-way MIDRANGE switch that offers different capacitors values in the Tone section. The OCTAVE switch's full bypass mode allows the 2nd stage to overdrive the 3rd stage even harder when the SUSTAIN control is cranked, providing a thicker tone. The MIDRANGE switch provide a deep scoop, a moderate scoop and almost no scoop. The only thing I did different was to use a 2N1308 germanium transistor as the 3rd stage. Not sure it makes an audible difference, but... Mojo. I used 2N5089s for the other three transistors, per the BOM. Octave diodes (upper left) are BAT46 and clipping diodes (bottom) are D2E. Note that the board is laid out for two different transistor pinouts: E-B-C and E-C-B. The generous parts spacing permitted me to use some of my fatter film caps. This is my first build with a Tayda copper hammer tone box. There was a so much paint in the holes that I had to chase the threads with a 6-32 tap. Labeling will be a challenge due to the textured finish. I originally put clear chickenhead knobs on. They looked great but didn't quite clear each other. The Aion mods could easily be applied to the PedalPCB Fuzzy Fox. No matter whose board you build, I highly recommend reading Aion's Build Docs. Although this pedal makes plenty of gain and volume (knob setting shown is for unity), it is possible to get considerably more volume by reducing the emitter resistor on the last stage. This circuit runs the bias fairly cold on all four transistors, probably because the original units were battery powered, making low current consumption desirable. The biases could be fiddled to obtain more gain, volume and/or headroom. I exercised some restraint and kept the stock bias settings.
