125B · 5 knobs
Boss HM-2 Heavy MetalVerified
Based on the Boss HM-2 Heavy Metal· 3 other boards clone it
- Category
- Distortion
- Controls
- Distortion · Low · Mids · High · Volume
- Build
- Perfboard
- Layout
- Verified · Effects Layouts (blog) marks it as built and working
- Tags
- Boss, Distortion
From the post
The HM-2 is the godfather of all other heavy metal distortion stompboxes. While it was first introduced in the '80s, it's still a highly regarded circuit for metal applications with its high gain and crushing lows, especially if you live in Sweden. Said crushing lows are thanks to the gyrator tone stack (not something you see all that often). Original units only have high and low tone controls, but it's easy to add a mids control, and the layout below reflects that. If you don't want the Mids control, simply connect the Mids 2 pad to lug 2 of the Highs pot. It's a fairly big layout, but you should be able to fit it in a 125B without issue, and if you're really precise with your drilling you might able to squeeze it into a 1590B.
Update July 13, 2016:
Updated the layout so that the ICs are getting full 9v. Tone stack pots may need to be reduced to 10k.
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 40 rows
Report a wrong parseGot parts in a drawer? See what you can build with them.
Check before you build · 1 value the reader of this layout was not sure of
- 1.5uF electrolytic at top left beside the first TL072: printed clearly, unusual value
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 16 | ||||
| ×9 | 10K | 10k | read from the layout by eye | |
| ×4 | 100K | 100k | read from the layout by eye | |
| ×3 | 330Ω | 330 | read from the layout by eye | |
| ×2 | 3.3K | 3.3k | read from the layout by eye | |
| ×2 | 22K | 22k | read from the layout by eye | |
| ×2 | 68K | 68k | read from the layout by eye | |
| ×2 | 470K | 470k | read from the layout by eye | |
| ×2 | 1M | 1M | read from the layout by eye | |
| ×1 | 22Ω | 22 | read from the layout by eye | |
| ×1 | 120Ω | 120 | read from the layout by eye | |
| ×1 | 150Ω | 150 | read from the layout by eye | |
| ×1 | 1K | 1k | read from the layout by eye | |
| ×1 | 4.7K | 4.7k | LED resistor; read from the layout by eye | |
| ×1 | 47K | 47k | read from the layout by eye | |
| ×1 | 82K | 82k | read from the layout by eye | |
| ×1 | 220K | 220k | read from the layout by eye | |
| Capacitors 12 | ||||
| ×3 | 10pF | 10p | read from the layout by eye | |
| ×1 | 1nF | 1n | read from the layout by eye | |
| ×1 | 4.7nF | 4.7n | read from the layout by eye | |
| ×1 | 6.8nF | 6.8n | read from the layout by eye | |
| ×4 | 47nF | 47n | read from the layout by eye | |
| ×1 | 68nF | 68n | read from the layout by eye | |
| ×1 | 100nF | 100n | read from the layout by eye | |
| ×1 | 150nF | 150n | read from the layout by eye | |
| ×2 | 1uF | 1u | electrolytic; read from the layout by eye | |
| ×1 | 1.5uF | 1.5u | electrolytic; read from the layout by eye | |
| ×2 | 10uF | 10u | electrolytic; read from the layout by eye | |
| ×2 | 47uF | 47u | electrolytic; read from the layout by eye | |
| Diodes 3 | ||||
| ×5 | 1N4148 | 1N4148 | printed 4148; read from the layout by eye | |
| ×2 | 1N34A | 1N34A | read from the layout by eye | |
| ×1 | 1N4001 | 1N4001 | printed 4001; read from the layout by eye | |
| Transistors 3 | ||||
| Q1 | BF245 | BF245 | JFET; read from the layout by eye | |
| Q2 | 2SC2240 | 2SC2240 | read from the layout by eye | |
| Q3 | 2SA970 | 2SA970 | read from the layout by eye | |
| ICs 1 | ||||
| ×3 | TL072 | TL072 | read from the layout by eye | |
| Potentiometers 5 | ||||
| Distortion | A250K | A250k | Potentiometer | read from the layout by eye |
| Low | B100K | B100k | Potentiometer | read from the layout by eye |
| Mids | B100K | B100k | Potentiometer | read from the layout by eye |
| High | B100K | B100k | Potentiometer | read from the layout by eye |
| Volume | A10K | A10k | Potentiometer | read from the layout by eye |
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