Enclosure not stated · 3 knobs
From the vendor
The blog author's overdrive/booster with an effects loop, designed for a friend to give old gain pedals new life: you put your gain pedal in the loop for more dynamics and warmth. A BS170 MOSFET gain stage with 1N34A germanium diodes clipping to ground feeds the FX send; the return goes through a 2N5457 JFET stage that also mixes in the MOSFET stage's source signal. Switches add bass (Bottom), set the brightness and add a Boost.
Schematic
The schematic is in the post. Open it at Revolution Deux. No KiCad fragment has been drawn for this circuit yet.
Parts list 34 rows
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Check before you build · 1 value the reader of this schematic was not sure of
- The protection diode at the BS170 gate is not given a part number.
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 8 | ||||
| R1 | 100K | 100k | read from the schematic by eye | |
| R2 | 1M | 1M | read from the schematic by eye | |
| R3 | 1M | 1M | read from the schematic by eye | |
| R4 | 4.7K | 4.7k | read from the schematic by eye | |
| R5 | 22K | 22k | read from the schematic by eye | |
| R6 | 1M | 1M | read from the schematic by eye | |
| R7 | 15K | 15k | read from the schematic by eye | |
| R8 | 390 | 390 | read from the schematic by eye | |
| Capacitors 15 | ||||
| C1 | 100n | 100n | read from the schematic by eye | |
| C2 | 2.2n | 2.2n | read from the schematic by eye | |
| C3 | 10n | 10n | via Bottom switch; read from the schematic by eye | |
| C4 | 47p | 47p | read from the schematic by eye | |
| C5 | 47p | 47p | read from the schematic by eye | |
| C6 | 100n | 100n | read from the schematic by eye | |
| C7 | 47n | 47n | read from the schematic by eye | |
| C8 | 47n | 47n | read from the schematic by eye | |
| C9 | 220n | 220n | read from the schematic by eye | |
| C10 | 15n | 15n | read from the schematic by eye | |
| C11 | 1n | 1n | read from the schematic by eye | |
| C12 | 10u | 10u | electrolytic; read from the schematic by eye | |
| C13 | 1u | 1u | electrolytic; read from the schematic by eye | |
| C14 | 4.7n | 4.7n | read from the schematic by eye | |
| C15 | 10n | 10n | read from the schematic by eye | |
| Diodes 3 | ||||
| D1 | ? | ? | protection diode, type not given; read from the schematic by eye | |
| D2 | 1N34A | 1N34A | germanium; read from the schematic by eye | |
| D3 | 1N34A | 1N34A | germanium; read from the schematic by eye | |
| Transistors 2 | ||||
| Q1 | BS170 | BS170 | read from the schematic by eye | |
| Q2 | 2N5457 | 2N5457 | read from the schematic by eye | |
| Potentiometers 3 | ||||
| Gain | A4.7K | A4.7k | Potentiometer | read from the schematic by eye |
| Bias trim | 10K | 10k | Potentiometer | trimmer, set for 5.5V on the drain; read from the schematic by eye |
| Volume | A1M | A1M | Potentiometer | read from the schematic by eye |
| Switches 3 | ||||
| Bottom | SPST | SPST | SW1; read from the schematic by eye | |
| Bright/Dark/Darker | DPDT on/off/on | DPDT ON/OFF/ON | SW2; read from the schematic by eye | |
| Boost | SPST | SPST | SW3; read from the schematic by eye | |