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GAINVOLUME

125B · 2 knobs

Aion FX

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

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RefValueNormalizedTypeNotes
Resistors 15
R11M1MMetal film resistor, 1/4W
R22k22.2kMetal film resistor, 1/4W
R310k10kMetal film resistor, 1/4W
R4680k680kMetal film resistor, 1/4W
R51k1kMetal film resistor, 1/4W
R61k51.5kMetal film resistor, 1/4W
R7680R680Metal film resistor, 1/4W
R8680R680Metal film resistor, 1/4W
R9100R100Metal film resistor, 1/4W
R1022k22kMetal film resistor, 1/4W
R111M1MMetal film resistor, 1/4W
R1247k47kMetal film resistor, 1/4W
R1347k47kMetal film resistor, 1/4W
RPD2M22.2MMetal film resistor, 1/4WInput pulldown resistor. Can be as low as 1M.
LEDR10k10kMetal film resistor, 1/4WLED current-limiting resistor. Adjust value to change LED brightness.
Capacitors 15
C110n10nFilm capacitor, 7.2 x 2.5mm
C2100pF100pMLCC capacitor, NP0/C0GSome schematics show 120pF here, but the Marshall factory schematic shows 100pF.
C3100n100nFilm capacitor, 7.2 x 2.5mm
C468n68nFilm capacitor, 7.2 x 2.5mmThe original has 220n and 100n capacitors in series, which makes 68n.
C5220pF220pMLCC capacitor, NP0/C0G
C6220n220nFilm capacitor, 7.2 x 2.5mm
C7100n100nFilm capacitor, 7.2 x 2.5mm
C8220n220nFilm capacitor, 7.2 x 2.5mm
C94n74.7nFilm capacitor, 7.2 x 2.5mm
C1010n10nFilm capacitor, 7.2 x 2.5mm
C1168n68nFilm capacitor, 7.2 x 2.5mm
C12470pF470pMLCC capacitor, NP0/C0G
C13100uF100uElectrolytic capacitor, 6.3mmPower supply filter capacitor.
C1447uF47uElectrolytic capacitor, 5mmReference voltage filter capacitor.
C15100n100nMLCC capacitor, X7RPower supply filter capacitor.
Diodes 9
D11N58171N5817Schottky diode, DO-41
D23mm3MMLED, 3mm, red diffused
D33mm3MMLED, 3mm, red diffused
D41N9141N914Fast-switching diode, DO-35
D51N9141N914Fast-switching diode, DO-35
D61N9141N914Fast-switching diode, DO-35
D71N9141N914Fast-switching diode, DO-35
D81N9141N914Fast-switching diode, DO-35
D91N9141N914Fast-switching diode, DO-35
ICs 1
IC1TL072TL072Operational amplifier, DIP8
Potentiometers 5
TREBLE10kBB10k16mm right-angle PCB mount pot
BASS10kAA10k16mm right-angle PCB mount pot
MID10kAA10k16mm right-angle PCB mount pot
GAIN100kBB100k16mm right-angle PCB mount pot
VOL100kBB100k16mm right-angle PCB mount pot
Switches 2
CLIPSPDT cntr offSPDT CNTR OFFToggle switch, SPDT on-off-on
FSW3PDT3PDTStomp switch, 3PDTAvailable from Aion FX.
LEDs 1
LED5mm5MMLED, 5mm, red diffused
Jacks & sockets 4
IC1-SDIP-8 socketDIP-8 SOCKETIC socket, DIP-8
IN1/4" stereo1/4" STEREO1/4" phone jack, closed frameSwitchcraft 112BX or equivalent.
OUT1/4" mono1/4" MONO1/4" phone jack, closed frameSwitchcraft 111X or equivalent.
DC2.1mm2.1MMDC jack, 2.1mm panel mountLumberg NEB/J 21 C or equivalent.
Hardware 2
BATTBattery snapBATTERY SNAP9V battery snapOptional. Use the soft plastic type—the hard-shell type will not fit.
ENC125B125BEnclosure, die-cast aluminumCan also use a Hammond 1590N1.

Other boards based on the Marshall Guv'nor