I've been looking at getting one as well, but also haven't seen them in stock. I'd rather not tread on Brian's toes as he is a great dude who always pops up on DIY threads. If anyone wants to read more, there was a
thread over on FSB where Brian chimed in both the Fuck & Mini circuits. Here are the notes I grabbed:
- "The Fuck has 3 JFET (2x J201, 1x 2N5457) gain stages in series with a dual-gang pot (Gain) controlling the volume of the first 2. The final 2N5089 is an Emitter Follower. SWTC for the High-Cut control. The rest of the components are for an envelope follower (aka the "dynamically modulated sag feature”). It's modulating the voltage on the 2N5457 for the crackle & gnar gnar. I tried modulating each different stage, two at a time & all three but the particular stage was the best choice for a number of reasons."
- "As for the gain stages, I chose straightforward values that worked well & kept it simple throughout the circuit. The beauty with such a basic circuit is that they can be tweaked to taste for the amount of treble/bass response, gain, etc."
- "I tried a few different envelope followers & always liked the crudeness of the Dr. Quack. It does indeed mis-bias the 2N5457. The yellow LED anode is connected to pin 5 of the TL072, set up for the offset-bias-trick used in many envelope-followers (Dr. Quack, etc.). Any envelope control circuit will work and can allow you to further tailor a pedal to your particular liking."
- "There are some other differences between the Mini & the Fuck since I wanted them to be different enough from each other to warrant the purchase of the two: Larger coupling capacitors, bass cut, static bias (or starve) control. But yeah, get this and you'll essentially have the Mini."
- "The Crackle toggle (DPDT) switches the operating mode of the Momentary Burst stomp - In one position, the pedal is in “Normal” mode and the momentary switch puts it into “Blown Amp" mode, and in the other position the normal state of the pedal is “Blown Amp” mode and the momentary puts it into “Normal” mode."
- "In the newer version I use a 10kB Threshold pot with a 10k trimpot in series to dial it in more precisely or to adjust for different pickup types). This works much better."
- "The expression input just controls the resistance of the Threshold knob - nothing fancy - i've probably only built a half-dozen with it included."
EDIT: NVM, maybe they are available?
https://www.smallsoundbigsound.com/products/fuck-overdrive/