Enclosure not stated · 2 knobs
Earthquaker Devices Crimson Drive (2-knob version)Verified
Based on the EarthQuaker Devices Crimson Drive (2-knob version)
From the post
Here's a good sounding overdrive from Earthquaker Devices. This is for the first incarnation of the Crimson Drive with just level and gain controls. Uses a J201 in a buffer stage and a PNP AC128 in the gain stage.
Dirk_Hendrik from FSB traced one and drew this schematic.
The power filter section makes me scratch my head a bit, as it uses 2, 100µ caps. To keep things a little simpler on the board I just put one 220µ cap, since the equivalent capacitance of two parallel capacitors is the sum of the individual capacitances.
Also note that the schematic calls for a low current LED, hence the 10k resistor from the power supply. Change that resistor to around 2.2k if you're using a more common LED.
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 21 rows
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| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 8 | ||||
| ×1 | 10K | 10k | read from the layout by eye | |
| ×1 | 2.2M | 2.2M | read from the layout by eye | |
| ×2 | 4.7K | 4.7k | read from the layout by eye | |
| ×2 | 1M | 1M | read from the layout by eye | |
| ×1 | 2.2K | 2.2k | read from the layout by eye | |
| ×1 | 68K | 68k | read from the layout by eye | |
| ×1 | 470K | 470k | read from the layout by eye | |
| ×1 | 15K | 15k | read from the layout by eye | |
| Capacitors 5 | ||||
| ×3 | 1uF | 1u | electrolytic; read from the layout by eye | |
| ×1 | 220uF | 220u | electrolytic; read from the layout by eye | |
| ×1 | 100uF | 100u | electrolytic; read from the layout by eye | |
| ×2 | 100nF | 100n | read from the layout by eye | |
| ×1 | 100pF | 100p | read from the layout by eye | |
| Diodes 3 | ||||
| D1 | 1N4148 | 1N4148 | read from the layout by eye | |
| ×2 | 1N60 | 1N60 | D2, D3; read from the layout by eye | |
| D4 | 1N4001 | 1N4001 | read from the layout by eye | |
| Transistors 2 | ||||
| Q1 | J201 | J201 | JFET; read from the layout by eye | |
| Q2 | AC128 | AC128 | read from the layout by eye | |
| Potentiometers 2 | ||||
| Gain | B100K | B100k | Potentiometer | read from the layout by eye |
| Level | A100K | A100k | Potentiometer | read from the layout by eye |
| LEDs 1 | ||||
| LED | Low current | LOW CURRENT | off-board indicator; legend 'LED: Low current'; read from the layout by eye | |