Enclosure not stated · 5 knobs
Dunwich Amplification Modified HM2 - DIY versionVerified
Based on the Dunwich Amplification Modified HM2 - DIY version
- Category
- Distortion
- Build
- Vero· 21×25· 40 cuts, 19 links
- Layout
- Verified · Dirtbox Layouts marks it as built and working
- Tags
- Distortion, Dunwich Amplification, HM-2
From the post
Dunwich released a small run of DIY PCBs a few years ago of a modified HM2. There is a few changes from a stock HM2 most noticable the on/off switches for both soft clipping and hard clipping diodes. You may want to experiment with the cap values at one of the gyrators for a more effective separate Mid control. AMZ and Griffin Effects have very useful bandpass filter/gyrator calculators.
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 Dirtbox Layouts. No KiCad fragment has been drawn for this circuit yet.
Parts list 45 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
- 4.7nF at column 18 near the top right: first digit partly hidden under a cut marker, reads '4,7nF'
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 14 | ||||
| ×3 | 330Ω | 330 | read from the layout by eye | |
| ×5 | 100K | 100k | read from the layout by eye | |
| ×1 | 82K | 82k | read from the layout by eye | |
| ×6 | 10K | 10k | read from the layout by eye | |
| ×2 | 3.3K | 3.3k | read from the layout by eye | |
| ×1 | 47K | 47k | read from the layout by eye | |
| ×1 | 20K | 20k | read from the layout by eye | |
| ×1 | 220K | 220k | read from the layout by eye | |
| ×1 | 120Ω | 120 | read from the layout by eye | |
| ×2 | 1M | 1M | read from the layout by eye | |
| ×2 | 22K | 22k | read from the layout by eye | |
| ×2 | 470K | 470k | read from the layout by eye | |
| ×1 | 22Ω | 22 | read from the layout by eye | |
| ×1 | 150Ω | 150 | read from the layout by eye | |
| Capacitors 12 | ||||
| ×1 | 1.5uF | 1.5u | read from the layout by eye | |
| ×1 | 68nF | 68n | read from the layout by eye | |
| ×2 | 470nF | 470n | 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 | |
| ×1 | 100nF | 100n | read from the layout by eye | |
| ×1 | 150nF | 150n | read from the layout by eye | |
| ×4 | 47nF | 47n | read from the layout by eye | |
| ×3 | 100pF | 100p | read from the layout by eye | |
| ×2 | 47uF | 47u | electrolytic; read from the layout by eye | |
| ×1 | 10uF | 10u | electrolytic; read from the layout by eye | |
| Diodes 7 | ||||
| D1 | Germanium | GERMANIUM | legend: Germanium or Shottky; read from the layout by eye | |
| D2 | Germanium | GERMANIUM | legend: Germanium or Shottky; read from the layout by eye | |
| D3 | Germanium | GERMANIUM | legend: Germanium or Shottky; read from the layout by eye | |
| D4 | 1N4148 | 1N4148 | legend: 1N4148/1N914; read from the layout by eye | |
| D5 | 1N4148 | 1N4148 | legend: 1N4148/1N914; read from the layout by eye | |
| D6 | 1N4148 | 1N4148 | legend: 1N4148/1N914; read from the layout by eye | |
| D7 | 1N5817 | 1N5817 | read from the layout by eye | |
| Transistors 3 | ||||
| Q1 | 2N5457 | 2N5457 | JFET; read from the layout by eye | |
| Q2 | 2N3904 | 2N3904 | read from the layout by eye | |
| Q3 | 2N3906 | 2N3906 | read from the layout by eye | |
| ICs 2 | ||||
| IC1 | TL072 | TL072 | read from the layout by eye | |
| IC2 | TL074 | TL074 | read from the layout by eye | |
| Potentiometers 5 | ||||
| Gain | A250K | A250k | Potentiometer | read from the layout by eye |
| Low | B10K | B10k | Potentiometer | read from the layout by eye |
| High | B10K | B10k | Potentiometer | read from the layout by eye |
| Mid | B10K | B10k | Potentiometer | optional, omit for stock HM2; read from the layout by eye |
| Volume | A100K | A100k | Potentiometer | read from the layout by eye |
| Switches 2 | ||||
| Soft Clip | SPST | SPST | toggle; read from the layout by eye | |
| Hard Clip | SPST | SPST | toggle; read from the layout by eye | |