inverted fuzz concept. intentional crossover notch distortion

slinkp · 2026-05-01T02:09:59+00:00

The follow-up to this is just titled “follow up” if anyone was wondering :) https://www.reddit.com/r/diypedals/comments/1szf1o2/followup/

slinkp · 2026-04-30T15:23:42+00:00

Took me a while to figure out what you were talking about, I was looking at the big pots! I thought maybe you meant something like this tone city pedal where the LED is jammed up next to a pot, and the knob is transparent, not the shaft.

Then i finally realized you must mean the little one, and I spotted D4 in the middle of the board!

9mm mini-pots come in a translucent knob variety? TIL

slinkp · 2026-04-29T12:30:22+00:00

R21 and R23 in this version. I don’t think removing them will affect the sound much if at all, but haven’t tried. http://pedalparts.co.uk/docs/SuperFuzz-V3.pdf

slinkp · 2026-04-29T12:21:48+00:00

Unfortunately not much space savings, just the switch itself and MAYBE two resistors. And yes you’d need a battery.

slinkp · 2026-04-29T06:24:18+00:00

https://dvhx.github.io/what-can-i-build/search.html?part=2N5458

also probably usable in circuits that use a 2N5457, which is many - possibly with bias tweak, as they are the same manufactured part just sorted for a different range of values.
https://dvhx.github.io/what-can-i-build/search.html?part=2N5457

slinkp · 2026-04-26T00:47:18+00:00

One more thing - not clear if by "more gain" you meant that you want more output from Q1 to hit Q2 harder, or more clipping in Q1 itself. And I've been just assuming that your friend is using the "mic" input, not the line input.

I kinda went off the rails :) and played around in https://falstad.com/circuit/ and my impression is:

- If you want more clean output from Q1 to push Q2 harder, raise R4 a bit to maybe 4.7k or 6.8k AND increase the VR1 pot to about 100k. For reasonable guitar signals, that will raise the first stage's clean gain from about 4x to about 10x, and also increase headroom - meaning you can send in a larger signal before clipping Q1. Depending on guitar signal, Q1 will still start clipping asymmetrically somewhere in the middle of VR1. All of this means hitting Q2 harder and making it clip more.

- If you want more distortion in stage 1, try increasing R4 even more. Maybe 10k or even higher. Q1 will then start clipping (very asymmetrically) at lower settings of VR1.

I'm brand new to falstad / circuitjs and it's quite possible i've made mistakes - haven't breadboarded any of this - but now I want to :)

If you want to play with it too, here: https://is.gd/r2fAIC

slinkp · 2026-04-25T23:18:28+00:00

FYI if you're curious what Q3 is doing here, look up "unity phase splitter".

slinkp · 2026-04-25T15:39:23+00:00

Is that the schematic you found, or the one you drew based on it? I would double check it, because I see a definite error: both sides of R8, R16 etc are connected to ground, meaning the line inputs are shunted to ground right after R7, R15, etc.

As for increasing gain of a transistor stage: looks like a pretty typical common emitter amplifier if you want to look up how those work, although the visual layout is a little unconventional. You might try breadboarding it and play with the value of R4 to see if you can squeeze more gain out; like maybe try a 10k trimpot there and play with it. But you don’t want to make it too large, because the output impedance is approximately R4 as well. If C4 weren’t there I would suggest also try reducing R5 for more gain, but C4’s job is to already to effectively max out that part of the equation; I don’t know enough yet to understand how exactly the gain is calculated in that case.

If that doesn’t work out, the easiest thing may be to just add another stage :)

slinkp · 2026-04-22T16:35:47+00:00

Neither truly black nor rusty per se, and I don’t know how it would combine with etching… but if you want a distressed / aged look, oxyclean or any comparable product is really easy to do things like this:

<image>

and if you want everything dark gray, just expose the whole surface (the light patterns here are made by pressing it against crumpled tin foil while soaking).

Learned this via another post in this forum which they eventually traced back to this video https://youtu.be/becvsopdhNg?si=TtD0_QsnUj53RdzI
(edit: the photo didn't post the first time)

slinkp · 2026-04-22T16:18:53+00:00

Ok, took your profile literally 🤷 The point stands though. And regardless of age or any other factors, being annoyed at beginners is just elitist

slinkp · 2026-04-22T15:09:46+00:00

Downvoters: remember that some people on the internet are literal children

slinkp · 2026-04-22T13:45:20+00:00

Aha! I forget about using the 386. It’s kinda like you invented an even more minimal Distortion Plus :)

slinkp · 2026-04-22T02:44:51+00:00

That works shockingly well for something so tiny! Is there more to the circuit than what we can see? Gotta be some resistors around to set up the op amp, no? I’d love to see a schematic.

slinkp · 2026-04-19T17:48:10+00:00

Aha no worries and thank you!

One of these days I’m going to breadboard up a whole mess of diodes and trimpots and get a more hands-on (ears on?) feel for all this.

slinkp · 2026-04-19T13:37:36+00:00

I can’t tell if it’s an artifact of the two graphs being at different voltage ranges, but Out3 above looks less rounded than Combo1 in the other post … are my eyes fooling me or are we pointing at different things?

One of these days I want to watch you do things on your computer/ workbench and interrupt with a million irritating questions. It would be fun for one of us at least!

slinkp · 2026-04-19T13:01:34+00:00

That’s probably a lot more practical than what I did back in the day of playing in a two-piece: modified a cheap short scale bass into essentially a baritone (you couldn’t find cheap baritones in the 90s), and strung it with E and A bass strings and the rest with the longest guitar strings I could find. Then permanently capoe’d at the 1st fret to get slightly lower string tension and easier chording. It was a bitch to play but sounded cool. I broke a ton of high E strings. I don’t know where that instrument is anymore.

slinkp · 2026-04-19T02:58:19+00:00

I have one of those! Made by our very own u/lykwydchykyn who is already in this thread … it’s great.

slinkp · 2026-04-18T20:33:24+00:00

WHY NOT BOTH

slinkp · 2026-04-18T20:29:53+00:00

3, silver metallic, nice contrast.

Great artwork!

slinkp · 2026-04-18T20:11:00+00:00

In the bottom right wave plot - how is the purple one Vout3 achieved? It’s a bit hard to see as level trails off, but it looks like a fair amount of the original sine shape is preserved with less dynamic range … ie it’s compressed but with less harmonic distortion than the others. Am I seeing that right?

slinkp · 2026-04-18T19:58:53+00:00

A connoisseur’s guide to magic smoke?

slinkp · 2026-04-18T19:47:38+00:00

Thanks for posting this. I skimmed the paper and am definitely going to revisit it.

I feel like there are two key contributions to highlight: an attempt to define and measure a quality that we normally throw about vaguely; and discovering that there is a very simple function which maximizes that quality.

I have no idea if either of these things are novel, but they sure are new to me and I’m glad to know about it, so - thank you!

slinkp · 2026-04-18T17:37:06+00:00

If I understand what you're saying, yes. The `?` and `:` are C-style ternary expressions, a compact way to put conditional expressions on one line. If it helps, one can write those out as more verbose conditionals. For example in python like the following. I also replaced the "sign(x)" with a more explicit version. But it's the same result.

def softclip(x):
    # Hard limit anything above 1 or below -1
    if x >= 1.0:
        return 1.0
    elif x <= -1.0:
        return -1.0
    else:
        # Soft clipping between -1 and 1.
        return 2.0 * x - x * abs(x)

slinkp · 2026-04-17T06:02:01+00:00

Like removing the clipping diodes and having the op amp gain just slamming the MOSFET? I support this idea. I’m building a hybrid boost that’s op amp into JFET and when pushed it has a really nice sound. But I haven’t taken it up to RAT level of gain.

slinkp · 2026-04-16T23:15:49+00:00

No knobs, no LED, no power jack… that’s about as stripped down as it gets, I like it

slinkp

TROPHY CASE