125B · 2 knobs
EquinoxAmp Overdrive
Based on the Marshall Guv'nor· 6 other boards clone it
- Category
- Overdrive
- Controls
- Gain · Volume
- Difficulty
- Easy
- Price
- $12.50in stock
From the vendor
A low-to-mid-gain overdrive featuring a unique dual-stage drive control and amp-like 3-band tone stack.
The Equinox Amp Overdrive project is a clone of the Marshall Guv’nor and Drivemaster. (The two pedals have different names, but they are identical circuits in every way except that the Guv’nor has an effects loop which has been excluded from this project).
First released in 1988, the Guv’nor was replaced in 1991 by the Drivemaster, the same time the Shredmaster and Bluesbreaker pedals were released. It was a very popular pedal at the time and remains well-regarded.
The Guv’nor was among the first overdrive pedals to use a 3-band tone control, allowing for more amp-like toneshaping via bass, midrange and treble knobs. Interestingly, while it looks like an amp tonestack on the surface, it’s actually a little closer to a Big Muff tone control in its technology. All three controls are much more interactive than you’d usually see on an amp.
The Equinox is faithful to the original, but with one added modification: a switch that lets you go between different clipping diodes. The original has a high clipping threshold using LEDs, but with the clipping switch you can also select two 1N914s in each direction, as in the Bluesbreaker, or one 1N914 in each direction, as in the Shredmaster.
Schematic
The schematic is in the vendor's build document, page 6. Open the build document. No KiCad fragment has been drawn for this circuit yet.
Parts list 54 rows
Report a wrong parse| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 15 | ||||
| R1 | 1M | 1M | Metal film resistor, 1/4W | |
| R2 | 2k2 | 2.2k | Metal film resistor, 1/4W | |
| R3 | 10k | 10k | Metal film resistor, 1/4W | |
| R4 | 680k | 680k | Metal film resistor, 1/4W | |
| R5 | 1k | 1k | Metal film resistor, 1/4W | |
| R6 | 1k5 | 1.5k | Metal film resistor, 1/4W | |
| R7 | 680R | 680 | Metal film resistor, 1/4W | |
| R8 | 680R | 680 | Metal film resistor, 1/4W | |
| R9 | 100R | 100 | Metal film resistor, 1/4W | |
| R10 | 22k | 22k | Metal film resistor, 1/4W | |
| R11 | 1M | 1M | Metal film resistor, 1/4W | |
| R12 | 47k | 47k | Metal film resistor, 1/4W | |
| R13 | 47k | 47k | Metal film resistor, 1/4W | |
| RPD | 2M2 | 2.2M | Metal film resistor, 1/4W | Input pulldown resistor. Can be as low as 1M. |
| LEDR | 10k | 10k | Metal film resistor, 1/4W | LED current-limiting resistor. Adjust value to change LED brightness. |
| Capacitors 15 | ||||
| C1 | 10n | 10n | Film capacitor, 7.2 x 2.5mm | |
| C2 | 100pF | 100p | MLCC capacitor, NP0/C0G | Some schematics show 120pF here, but the Marshall factory schematic shows 100pF. |
| C3 | 100n | 100n | Film capacitor, 7.2 x 2.5mm | |
| C4 | 68n | 68n | Film capacitor, 7.2 x 2.5mm | The original has 220n and 100n capacitors in series, which makes 68n. |
| C5 | 220pF | 220p | MLCC capacitor, NP0/C0G | |
| C6 | 220n | 220n | Film capacitor, 7.2 x 2.5mm | |
| C7 | 100n | 100n | Film capacitor, 7.2 x 2.5mm | |
| C8 | 220n | 220n | Film capacitor, 7.2 x 2.5mm | |
| C9 | 4n7 | 4.7n | Film capacitor, 7.2 x 2.5mm | |
| C10 | 10n | 10n | Film capacitor, 7.2 x 2.5mm | |
| C11 | 68n | 68n | Film capacitor, 7.2 x 2.5mm | |
| C12 | 470pF | 470p | MLCC capacitor, NP0/C0G | |
| C13 | 100uF | 100u | Electrolytic capacitor, 6.3mm | Power supply filter capacitor. |
| C14 | 47uF | 47u | Electrolytic capacitor, 5mm | Reference voltage filter capacitor. |
| C15 | 100n | 100n | MLCC capacitor, X7R | Power supply filter capacitor. |
| Diodes 9 | ||||
| D1 | 1N5817 | 1N5817 | Schottky diode, DO-41 | |
| D2 | 3mm | 3MM | LED, 3mm, red diffused | |
| D3 | 3mm | 3MM | LED, 3mm, red diffused | |
| D4 | 1N914 | 1N914 | Fast-switching diode, DO-35 | |
| D5 | 1N914 | 1N914 | Fast-switching diode, DO-35 | |
| D6 | 1N914 | 1N914 | Fast-switching diode, DO-35 | |
| D7 | 1N914 | 1N914 | Fast-switching diode, DO-35 | |
| D8 | 1N914 | 1N914 | Fast-switching diode, DO-35 | |
| D9 | 1N914 | 1N914 | Fast-switching diode, DO-35 | |
| ICs 1 | ||||
| IC1 | TL072 | TL072 | Operational amplifier, DIP8 | |
| Potentiometers 5 | ||||
| TREBLE | 10kB | B10k | 16mm right-angle PCB mount pot | |
| BASS | 10kA | A10k | 16mm right-angle PCB mount pot | |
| MID | 10kA | A10k | 16mm right-angle PCB mount pot | |
| GAIN | 100kB | B100k | 16mm right-angle PCB mount pot | |
| VOL | 100kB | B100k | 16mm right-angle PCB mount pot | |
| Switches 2 | ||||
| CLIP | SPDT cntr off | SPDT CNTR OFF | Toggle switch, SPDT on-off-on | |
| FSW | 3PDT | 3PDT | Stomp switch, 3PDT | Available from Aion FX. |
| LEDs 1 | ||||
| LED | 5mm | 5MM | LED, 5mm, red diffused | |
| Jacks & sockets 4 | ||||
| IC1-S | DIP-8 socket | DIP-8 SOCKET | IC socket, DIP-8 | |
| IN | 1/4" stereo | 1/4" STEREO | 1/4" phone jack, closed frame | Switchcraft 112BX or equivalent. |
| OUT | 1/4" mono | 1/4" MONO | 1/4" phone jack, closed frame | Switchcraft 111X or equivalent. |
| DC | 2.1mm | 2.1MM | DC jack, 2.1mm panel mount | Lumberg NEB/J 21 C or equivalent. |
| Hardware 2 | ||||
| BATT | Battery snap | BATTERY SNAP | 9V battery snap | Optional. Use the soft plastic type—the hard-shell type will not fit. |
| ENC | 125B | 125B | Enclosure, die-cast aluminum | Can also use a Hammond 1590N1. |
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