The Vulcan is a heavy over to distortion by Joe Davisson. Check his Analog Alchemy page for more of his designs. Here’s a discussion of the circuit over at the DIYStompboxes forum.
![](https://i0.wp.com/www.super-freq.com/wp-content/uploads/2020/12/9D38F5EC-1572-4A12-B6BB-515FCBAA2567-540x720.jpeg?resize=540%2C720)
You can order these boards from PCBWays chared service and build this project for yourself.
https://www.pcbway.com/project/shareproject/Vulcan_Overdrive_Distortion_640f507b.html
![](https://i0.wp.com/www.super-freq.com/wp-content/uploads/2022/01/CA286885-4B62-4564-A863-166D3978CF88-scaled.jpeg?resize=1440%2C1920)
![](https://i0.wp.com/www.super-freq.com/wp-content/uploads/2022/01/45FD0B41-4784-4BEC-B2C0-63966ED1BD94-scaled.jpeg?resize=1440%2C1920)
![](https://i0.wp.com/www.super-freq.com/wp-content/uploads/2022/01/C5352A6C-6128-4EFB-8E31-9174BC9CF4B3-scaled.jpeg?resize=1440%2C1920)
Bill of Materials
Part | Value |
C1 | 100n |
C2 | 100n |
C3 | 100n |
C4 | 2n2 |
C5 | 100n |
C6 | 100n |
C7 | 22µ |
C8 | 22µ |
C9 | 22µ |
C10 | 100µ |
C11 | 47n |
D1 | 1N914 |
D2 | 1N914 |
D3 | 1N914 |
D4 | LED |
D5 | 1N5817 |
Q1 | 2N5089 |
Q2 | 2N5089 |
Q3 | 2N5089 |
GAIN | A1M |
VOLUME | A100K |
R1 | 1M |
R2 | 1M |
R3 | 4M7 |
R4 | 10K |
R5 | 1K |
R6 | 470K |
R7 | 1M |
R8 | 4M7 |
R9 | 10K |
R10 | 1K |
R11 | 470K |
R12 | 1M |
R13 | 4M7 |
R14 | 10K |
R15 | 1K |
RLED | 1K-10K (adjust to taste) |
![](https://i0.wp.com/www.super-freq.com/wp-content/uploads/2021/08/Vulcan-v1-Schematic.png?resize=1934%2C654)
![](https://i0.wp.com/www.super-freq.com/wp-content/uploads/2021/08/Artboard.png?resize=562%2C1084)
![](https://i0.wp.com/www.super-freq.com/wp-content/uploads/2021/08/Artboard-Drill-2.png?resize=1336%2C1944)