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Zeners have higher capacitance that other diodes, which could make a difference at higher DRIVE settings. Try a 1N4148 & a GE diode in series, that gets pretty close. Most Si transistor E-B junctions should work well. The B-C junction has a higher Vf, if you want that.

Apparently no one has built one of these yet because the schematic in post #1 had a serious typo. It's fixed now. If you DL'ed that schematic, delete it and replace it with the one above dated 29-Nov-2025.

JFETs are used as analog switches in Boss, Ibanez & many other pedals. They are used as audio amplifiers & RF amplifiers. You'll find them used in preamps inside microphones. They are used as voltage-controlled resistors in phase-shifters such as the Phase 90 and compressors such as in the...

I think it's just the nature of the beast. It's mainly due to the fact that JFETs are depletion devices, meaning that with zero Vgs, they are full on and to use them as amplifiers you have to deplete the charge carriers by biasing them towards off. JFETs are made from very pure silicon and...

R6 is the anti-pop resistor for the BOOST switch. It's R5 in the PPCB build Docs. https://docs.pedalpcb.com/project/MojitoDeluxe-PedalPCB.pdf

I used to do detailed noise analysis as part of my job. Not a simple task and SPICE doesn't necessarily do a good job predicting noise. Opamp models rarely contain noise sources. Noise analysis has to take the entire circuit into account. We can't just look at one component in isolation and...

You might as well increase R58 & R47 by 10x or more since there is no DC current flowing in R51, then you can make C46 proportionately smaller. I'd make R51 1M and C21 1uF. Same time-constant, higher impedance.

I think you mean R5 & R14. They do just what you say, they limit the voltage swing toward ground. This affects the symmetry of the clipping. That's the only reason I can think of for having those resistors in series with Q1 & Q3. Let's look at one example, Q1 & Q2. Q2-S will be biased above...

Similar in some ways, different in others. They both have hard clipping with at least one Ge diode. The Hi-Cut is similar, but the other EQs are different. SS3 has no MID control. I had to go back and update the schematic in post #10. D2 is supposed to be a Ge diode.

You're going to call it "Bloody Germanium Crush" and there's no Germanium in it? 🤬👎 But seriously, Schottky is a poor sub for Ge. At least put some resistance in series with the Schottkys. BTW, my last version sounded like crap with the MID switch in the deep scoop position (green curve)...

I made that statement on Dec 29, 2020. The build docs were released in July of 2021. There is no reason to expect the ref des to be the same. The schematic in this thread identifies C18 as the power supply bypass cap. It's C100 in the build docs. If you make sure that every part is rated...

The only reason you can get away with leaving out the 100uF power supply bypass cap is because Robert put one on the circuit board. It's still a good idea to have local bypass on the power rails. You're saying that from 0 (7:00) to 1 (8:00) not much goes on. I suppose that makes sense. Above...

The red curve is too congested in the midrange. Tried it with a Tele and a LP. I'm trying this tuning (same knob settings):

This is the Tone Stack's freq response, from U1-1 to U1-5 with BASS at 7, TREBLE at 6. Green & blue curves are the current MID switch settings. I'm thinking about adding the red curve on the 3rd position. I'll let you know how it turns out.

Some people are just never satisfied. :p I'll try some other values. Are you looking for deeper mid scoop?

The biggest difference is the diodes. Swap those out, tweak the trimpots and they should sound the same.

This is something that HamishR & II have been messing with for a few days. It's kind of an an outgrowth of the ChuckMeister. It started with HamishR taking the 1st half of the ChuckMeister (he call his version the Shredmaster) and stacking it with a circuit we call The Beast. Then we started...

Those long wires don't help. Try to shorten the input & GAIN pot wires. This thing has a max gain of 500x and any cross-talk between wires can cause oscillation. A 100nF cap from pin 4 to pin 7 would be good too.

The cap is small enough that the opamp (even a shitty little 741) will fight it and win. Sticking a cap from the output of an opamp to ground is usually a bad idea because it either does nothing, or makes the opamp oscillate. The only exception is OTAs because their output impedance is very high.

I've been meaning to breadboard this 1 2. Maybe I'll build V2. Have you tried rolling opamps? LF351, TL071, OP07, LM308, CA3130... I doubt C4 does anything.