Last Breadboard for 2023: Devi Ever Disaster Fuzz

[Chuck D. Bones]

Unruly fuzzes are normally not my thing, but I wanted to expand my horizons a bit. So here goes. It fuzzes, it gates, it oscillates, and it's controllable from the guitar. I made a few minor mods to the design I found on Tagboardeffects (yes, I had to trace the Vero).
I changed:

1. D1, which was a 2N2222, to a 1N4148. The transistor was wired as a diode with E connected to C1, B connected to Q1-B and C connected to nothing. Works fine either way.
2. C2 & C3 from 20nF, which I don't have, to 22nF.
3. VOLUME from B100K to A100K.
4. Added DISASTER pot VR3 in place of the DISASTER switch so I could fine-tune the tone and oscillations. For a Krackle Fuzz, omit the DISASTER pot or switch. Or put a momentary stomp switch in series with the DISASTER pot.

I had to simulate this first to see what I should expect.
With no signal and DISASTER at 0, Q2 is saturated and the output is quiet. Depending on the CONTROL setting, the slightest sound from the guitar will open the gate and let the ripping tones come out. Note decay is extremely crunchy, like walking on corn flakes. With DISASTER turned up, this circuit breaks into oscillation which may or may not be affected by the guitar signal. Turning the guitar's knobs will vary the pitch and volume of the oscillation. With the right DISASTER setting, the oscillations will die out as the guitar signal decays. Couple this with a wah-wah & a delay and you can annoy your bandmates for hours.


L-R: VOLUME - DISASTER - CONTROL Setting shown are for extreme chaos.

 

[cdwillis]

I see you left the control pot wired the Devi way. One of the first pedals I built was a Soda Meiser on vero board and I found the control knob to barely work worth a damn. I'm not sure if it's because it was wired with input the wiper or it's just the overall circuit design. I always meant to go back and breadboard it with a logarithmic control pot wired up as a voltage divider, maybe with a treble bleed.

 

[Chuck D. Bones]

I've seen a few other pedal designs that wired the GAIN or VOLUME pot that way. It looks wrong, but when the value and taper are right, it works. Coupled with the DISASTER switch/pot, the "backwards" control pot makes sense in this circuit.

It's anyone's guess what a brite cap will do on a DE pedal.