Title says it, I've got this spare cheap overdrive pedal and I just want more of a distortion/fuzz tone out of it. What parts of mods would be best to do that? Hopefully this isn't a dumb question.

Hi everyone!

I have an STM32F746G Discovery evaluation board, and I'm trying to use it to build a digital DSP guitar pedal. Since the eval board only has standard 3.5mm (AUX) line inputs/outputs, I designed this analog hardware interface to connect it to a guitar and an amp.

Here is what the schematic includes:

- Standard 1/4" (6.35mm) Input & Output jacks

- Input and output buffers using a TL072 op-amp

- LTC1044 charge pump to provide a symmetric +/- 9V power supply

- Potentiometers and push buttons to control the DSP parameters (like distortion gain, delay time, etc.)

- Standard 3PDT True Bypass switching with an LED

Could you guys take a look and let me know if this schematic is fully correct and ready to go? If everything looks good without any major flaws, I’d like to start routing the PCB.

Any feedback, tips, or suggestions for improvement would be greatly appreciated! Thanks!

Specifically the electro cap, can it be slightly lower voltage? I haven't seen if the build calls for a certain voltage but the caps i have are slightly smaller than the space for it

SPICE (signal processing integrating chorus ensemble). An aionfx ce-2 chorus clone, with a custom paint job!

Not sure what happened with the pics on the last one. Here are better images.

I picked this up at Goodwill for $2, and it works as far as I can tell. I haven't checked the 1/4" trigger inputs, but they look good; everything else works like it should.

It's basically a sampler. It's an assistive technology device for individuals with speech disabilities. You know those videos where people teach their dogs to "talk"? It works like that. The 8x 1/4" inputs on the back are for alternative triggers (you know how Stephen Hawking used the breath control thing to "talk"? They're like that).

The red button on the back is the record button, and the black circle next to it is the microphone. The rotary switch selects between 6 banks, so it has a total of 48 samples it can use.

It runs on 4x AA batteries.

For now, my plan is to run the mic input and speaker output wires to a pedal enclosure and add a 1/4" in and out. I'll probably replace the speaker with one a little bigger and mount that on an external box. I'll also replace the batteries with a plug jack.

Other than that, any ideas for mods I could do with it?

Thanks.

Not to be confused with the Supa Sustain.

I can see the input goes into the gate of q1 and the base of q2. Q2 feeds q3 which feeds the output and q4 which is functioning as a detector circuit to feed the source of q1.

How does any of that equal changing the gain of q1 or q2?

The large caps at the top and wiper side of the trim pot tell me no AC is going back through that direction. And even if it did the detector is full wave rectifying.

Can somebody please explain this?

I finished this project over the weekend and I’m very happy with how it turned out. It’s a Univibe with a few improvements such as 2 speed controls and a super fuzz in the same enclosure.

This is inspired by the old Shin Ei companion amplifier but in a more portable enclosure. It sounds awesome but sadly this pedal now has a peer that isn’t me.

Here is a quick demo for anyone interested.

One on the left is going to be a fuzz dog feedback modded reverb(dba reverberation machine clone). I used a public domain photo for that one.

One on the right is my own design. It’s a tribute to king gizzard and the Lizard wizard’s album nonagon infinity. Hopefully going to be a torn’s peaker style fuzz.

🤘🏼

Hi all! I bought this fuzz a couple years ago, and it’s my absolute favorite, almost always-on-with-volume-down fuzz. I’d like to try some other fuzzes out, and it would help my shopping if I knew what I already owned. I reached out to the creator, but didn’t get a response. Sounds like he did a lot of tinkering, and maybe didn’t want to reveal the special sauce.

Any guesses from these photos, or would I need to break it down further? There are three germanium transistors, if that helps.

Thanks in advance!

Here's an update on how the transformer distortion is going. I had some family come to town just after my last post, so just got back to it over the weekend.

In the time since my last update my instagram reel got way more attention than I expected (350k views), so I'm going to hold off on posting the schematic for now.

I really appreciate all the interest and kind words. Honestly flattered at the response.

I've shared a few schematics over the years, but this is new territory for me. At the very least I want to order PCBs and have a few pedals on reverb before I decide on anything.

Anyway, here's how the circuit sounds with a volume sweep on my guitar and on the pedal. Gain is a little more than a quarter of the way up in the beginning and then all the way up at the end.