Enclosure not stated · 3 knobs
Revolution Deux Mixer/Switching System
Based on the Fred Briggs Mixer/Switching System
From the vendor
Fred Briggs' wet/dry mixer and effects-loop switcher, built to rehouse a Behringer RM600 Reverb Machine running 100% wet. A Super Hard On style BS170 MOSFET preamp with a Pregain control buffers the input, the wet path goes out and back through a loop with two-pole low-pass filtering to soften the reverb's noise, and TL084 buffers isolate the dry and wet paths before they are summed with Dry Level and Wet Level controls; the fourth op-amp makes the half-supply bias. He notes it works for other bargain digital pedals too, such as the Behringer EM600 Echo Machine.
Use switched jacks for the FX loop. The drawing suggests dual outputs for a 'stereo' wet and dry out, and a switched jack for the wet signal.
Schematic
The schematic is in the post. Open it at Revolution Deux. No KiCad fragment has been drawn for this circuit yet.
Parts list 35 rows
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Check before you build · 1 value the reader of this schematic was not sure of
- The Wet Level pot taper letter is unclear ('47KS'); the Dry Level pot reads 47KB.
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 15 | ||||
| R1 | 2.2M | 2.2M | input pull-down; read from the schematic by eye | |
| R2 | 1M | 1M | gate bias; read from the schematic by eye | |
| R3 | 1M | 1M | gate to ground; read from the schematic by eye | |
| R4 | 5.1K | 5.1k | drain; read from the schematic by eye | |
| R5 | 470 | 470 | source; read from the schematic by eye | |
| R6 | 10K | 10k | return low-pass filter; read from the schematic by eye | |
| R7 | 10K | 10k | return low-pass filter; read from the schematic by eye | |
| R8 | 240K | 240k | bias to Vr; read from the schematic by eye | |
| R9 | 100K | 100k | wet mix; read from the schematic by eye | |
| R10 | 10K | 10k | dry path; read from the schematic by eye | |
| R11 | 240K | 240k | bias to Vr; read from the schematic by eye | |
| R12 | 100K | 100k | dry mix; read from the schematic by eye | |
| R13 | 100K | 100k | output pull-down; read from the schematic by eye | |
| R14 | 10K | 10k | Vr divider; read from the schematic by eye | |
| R15 | 10K | 10k | Vr divider; read from the schematic by eye | |
| Capacitors 12 | ||||
| C1 | 100n | 100n | input; read from the schematic by eye | |
| C2 | 4.7u | 4.7u | electrolytic; read from the schematic by eye | |
| C3 | 4.7u | 4.7u | electrolytic, FX send; read from the schematic by eye | |
| C4 | 4.7u | 4.7u | electrolytic, FX return; read from the schematic by eye | |
| C5 | 3.3n | 3.3n | read from the schematic by eye | |
| C6 | 3.3n | 3.3n | read from the schematic by eye | |
| C7 | 4.7u | 4.7u | electrolytic; read from the schematic by eye | |
| C8 | 2.2n | 2.2n | read from the schematic by eye | |
| C9 | 4.7u | 4.7u | electrolytic; read from the schematic by eye | |
| C10 | 4.7u | 4.7u | electrolytic, output; read from the schematic by eye | |
| C11 | 47u | 47u | electrolytic, power filter; read from the schematic by eye | |
| C12 | 10u | 10u | electrolytic; read from the schematic by eye | |
| Diodes 1 | ||||
| D2 | 1N4001 | 1N4001 | read from the schematic by eye | |
| Transistors 1 | ||||
| Q1 | BS170 | BS170 | MOSFET; read from the schematic by eye | |
| ICs 1 | ||||
| IC1 | TL084 | TL084 | quad op-amp; read from the schematic by eye | |
| Potentiometers 3 | ||||
| Pregain | 4.7K | 4.7k | Potentiometer | source leg; read from the schematic by eye |
| Dry Level | B47K | B47k | Potentiometer | read from the schematic by eye |
| Wet Level | 47K | 47k | Potentiometer | read from the schematic by eye |
| Switches 1 | ||||
| Verb on/off | SPDT | SPDT | read from the schematic by eye | |
| LEDs 1 | ||||
| D1 | red LED | RED LED | gate protection; read from the schematic by eye | |