Enclosure not stated · 7 knobs
Dunwich Amplification DA-120 Overdrive V1Verified
Based on the Dunwich Amplification DA-120 Overdrive V1
- Category
- Preamp / Amp-in-a-box
- Build
- Vero· 22×25· 40 cuts, 21 links
- Layout
- Verified · Dirtbox Layouts marks it as built and working
- Tags
- Amp Emulator, Distortion, Dunwich Amplification, Matamp, Overdrive
From the post
Here is a layout of an early version of D-120 OD. It is basically a J FET conversion of a Matamp GT120 with some interesting tweaks like diodes connected to the sources for some of the transistors. It also have a clean blend /summing amp circuit. The original had fixed resistors across drain and V for Q1 through Q3 but I replaced them with 50k trimpots for easier bias setup. Note that the more recent revisions is a completely different beast circuit wise with a rotary switch, MOSFET transistors and a quad op amp.
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 33 rows
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Check before you build · 1 value the reader of this layout was not sure of
- D1 (left edge, rows T-V): legend says only 'Shottky', no part number given
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 9 | ||||
| ×7 | 100K | 100k | read from the layout by eye | |
| ×3 | 10M | 10M | read from the layout by eye | |
| ×3 | 10K | 10k | read from the layout by eye | |
| ×2 | 1M | 1M | read from the layout by eye | |
| ×1 | 100Ω | 100 | read from the layout by eye | |
| ×1 | 2.2K | 2.2k | read from the layout by eye | |
| ×1 | 27K | 27k | read from the layout by eye | |
| ×1 | 68K | 68k | read from the layout by eye | |
| ×1 | 220K | 220k | read from the layout by eye | |
| Capacitors 8 | ||||
| ×1 | 330pF | 330p | read from the layout by eye | |
| ×1 | 1nF | 1n | read from the layout by eye | |
| ×2 | 2.2nF | 2.2n | read from the layout by eye | |
| ×1 | 10nF | 10n | read from the layout by eye | |
| ×3 | 47nF | 47n | read from the layout by eye | |
| ×4 | 100nF | 100n | one is a ceramic disc; read from the layout by eye | |
| ×1 | 10uF | 10u | electrolytic; read from the layout by eye | |
| ×5 | 47uF | 47u | electrolytic; read from the layout by eye | |
| Diodes 3 | ||||
| D1 | Schottky | SCHOTTKY | legend: 'Shottky', no part number; read from the layout by eye | |
| ×2 | 1N4148 | 1N4148 | D2, D3; legend: 1N4148/1N914; read from the layout by eye | |
| D4 | 1N5817 | 1N5817 | read from the layout by eye | |
| Transistors 1 | ||||
| ×4 | J201 | J201 | Q1-Q4, JFET; read from the layout by eye | |
| ICs 2 | ||||
| IC1 | TL072 | TL072 | read from the layout by eye | |
| IC2 | MAX1044 | MAX1044 | legend: MAX1044/ICL7660S/LTC1144; read from the layout by eye | |
| Potentiometers 7 | ||||
| Drive | C5K | C5k | Potentiometer | read from the layout by eye |
| Gain | A1M | A1M | Potentiometer | read from the layout by eye |
| Treble | A1M | A1M | Potentiometer | read from the layout by eye |
| Bass | A1M | A1M | Potentiometer | read from the layout by eye |
| Boost | A250K | A250k | Potentiometer | read from the layout by eye |
| Clean | A100K | A100k | Potentiometer | read from the layout by eye |
| Volume | A100K | A100k | Potentiometer | read from the layout by eye |
| Trimmers 2 | ||||
| ×1 | 25K | 25k | read from the layout by eye | |
| ×3 | 50K | 50k | read from the layout by eye | |
| Switches 1 | ||||
| Depth Sw | SPST | SPST | toggle; read from the layout by eye | |