Enclosure not stated · 3 knobs
Evil Harmonic OverdriverVerified
Based on the Evil Harmonic Overdriver
From the post
For Fuzz Friday here's a really cool circuit designed by Lubdar over on the Madbean forum. It's inspired by Death by Audio designs and can go from overdrive to full on fuzz. If you can't get a DBA design working, give this one a shot. Here's what he had to say about it:
It's a combination of ideas from the newer Evil Fuzz/Harmonic Transformer/Interstellar Overdriver.It is comprised of 2 reverse beta gain stages, with level controls for each, that way you can turn level1 all the way down and get fairly clean overdrive tones, or max it out for fuzz, and anywhere in between. The density knob controls the input capacitance for thin treble all the way to bass bass bass. The toggles are for switching out a transistor stage in the 1st gain stage, and the second is an output pulldown resistor to give a slight volume boost.
Schematic
This is a board layout, a drawing of where each part goes, and the post may link the schematic it was drawn from. Open the layout at Effects Layouts (blog). No KiCad fragment has been drawn for this circuit yet.
Parts list 24 rows
Report a wrong parseGot parts in a drawer? See what you can build with them.
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 8 | ||||
| ×1 | 1K | 1k | read from the layout by eye | |
| ×5 | 910K | 910k | read from the layout by eye | |
| ×5 | 180K | 180k | read from the layout by eye | |
| ×1 | 100Ω | 100 | read from the layout by eye | |
| ×1 | 15K | 15k | read from the layout by eye | |
| ×1 | 1M | 1M | read from the layout by eye | |
| ×2 | 390Ω | 390 | read from the layout by eye | |
| ×1 | 100K | 100k | read from the layout by eye | |
| Capacitors 5 | ||||
| ×6 | 100nF | 100n | read from the layout by eye | |
| ×1 | 10nF | 10n | read from the layout by eye | |
| ×2 | 680nF | 680n | read from the layout by eye | |
| ×1 | 470nF | 470n | read from the layout by eye | |
| ×1 | 220uF | 220u | electrolytic; read from the layout by eye | |
| Diodes 1 | ||||
| ×1 | 1N4001 | 1N4001 | read from the layout by eye | |
| Transistors 5 | ||||
| Q1 | MPSA05 | MPSA05 | read from the layout by eye | |
| Q2 | MPSA05 | MPSA05 | read from the layout by eye | |
| Q3 | MPSA05 | MPSA05 | read from the layout by eye | |
| Q4 | MPSA05 | MPSA05 | read from the layout by eye | |
| Q5 | MPSA05 | MPSA05 | read from the layout by eye | |
| Potentiometers 3 | ||||
| Pre | A100K | A100k | Potentiometer | read from the layout by eye |
| Density | B100K | B100k | Potentiometer | read from the layout by eye |
| Post | A100K | A100k | Potentiometer | read from the layout by eye |
| Switches 2 | ||||
| Shape | SPDT | SPDT | read from the layout by eye | |
| Boost | SPST | SPST | read from the layout by eye | |