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EQUINOX AMP OVERDRIVE

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PROJECT NAME

EQUINOX

BASED ON

EFFECT TYPE

PROJECT SUMMARY

DOCUMENT VERSION

Marshall Guv’nor (Drivemaster)

A great low-to-mid-gain amp-like overdrive with a 3-band EQ.

Amp-Like Overdrive

1.0.2(2021-04-27)

BUILD DIFFICULTY

Easy

Actual size is 2.3” x 1.86” (main board) and 2.3” x 0.86” (bypass board).

Summary of Contents for EQUINOX

Page 1: ...EFFECT TYPE PROJECT SUMMARY DOCUMENT VERSION Marshall Guv nor Drivemaster A great low to mid gain amp like overdrive with a 3 band EQ Amp Like Overdrive 1 0 2 2021 04 27 BUILD DIFFICULTY Easy Actual size is 2 3 x 1 86 main board and 2 3 x 0 86 bypass board ...

Page 2: ... 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...

Page 3: ... film resistor 1 4W RPD 2M2 Metal film resistor 1 4W Input pulldown resistor Can be as low as 1M LEDR 4k7 Metal film resistor 1 4W LED current limiting resistor Adjust value to change LED brightness C1 10n Film capacitor 7 2 x 2 5mm C2 100pF MLCC capacitor NP0 C0G Some schematics show 120pF here but the Marshall factory schematic shows 100pF C3 100n Film capacitor 7 2 x 2 5mm C4 68n Film capacitor...

Page 4: ...e PCB mount pot BASS 10kA 16mm right angle PCB mount pot MID 10kA 16mm right angle PCB mount pot GAIN 100kB 16mm right angle PCB mount pot VOL 100kB 16mm right angle PCB mount pot CLIP SPDT cntr off Toggle switch SPDT on off on LED 5mm LED 5mm red diffused IN 1 4 stereo 1 4 phone jack closed frame Switchcraft 112BX or equivalent OUT 1 4 mono 1 4 phone jack closed frame Switchcraft 111X or equivale...

Page 5: ...ster If you look at the schematic you ll see that the LEDs D2 and D3 are always connected However in either the up or down switch positions the lower threshold diodes are connected and so the LEDs have no effect there s no signal remaining for them to clip The only thing to be aware of is that since the Guv nor does not have a gain recovery stage after the clipping diodes passive tone stack like t...

Page 6: ...8n 220pF 220n 100n 220n 4n7 10n 10kA 10kA 10kB GND 100kB GND GND GND 10uF GND GND 1M 470pF GND GND 68n GND VB VB VB VA GND GND GND RPD D1 C13 IN OUT C15 R2 R3 R4 R5 R6 R7 R8 R9 R10 R1 R12 R13 C1 IC1A 2 3 1 C2 C3 GAIN 1 2 3 IC1B 6 5 7 8 4 C4 C5 C6 C7 C8 C9 C10 BASS 1 2 3 MID 1 2 3 TREBLE 1 2 3 VOLUME 1 2 3 C14 R11 C12 C11 D4 D5 D7 D6 CLIP 2 3 1 D9 D8 D2 D3 GND ...

Page 7: ...like the Switchcraft 111X Open frame jacks will not fit in layouts with 5 or more knobs due to the placement of the DC jack LED hole drill size assumes the use of a 5mm LED bezel available from several parts suppliers Adjust size accordingly if using something different such as a 3mm bezel a plastic bezel or just a plain LED 0 1 2 CM 0 1 INCH x 0 775 y 1 71 x 0 775 y 1 71 ø9 32 ø9 32 x 0 775 y 0 4...

Page 8: ...EQUINOX AMP OVERDRIVE 8 ENCLOSURE LAYOUT Enclosure is shown without jacks See next page for jack layout and wiring 125B ...

Page 9: ...RAM 125B IN V GND N C N C OUT PCB IN GND V V JACK GND JACK OUT IN GND GND PCB OUT Shown with optional 9V battery If battery is omitted both jacks can be mono rather than one being stereo Leave the far right lug of the DC jack unconnected ...

Page 10: ...ndeavors in any quantity unless specifically noted No attribution is necessary though a link back is always greatly appreciated The only usage restrictions are that 1 you cannot resell the PCB as part of a kit without prior arrangement and 2 you cannot goop the circuit scratch off the screenprint or otherwise obfuscate the circuit to disguise its source In other words you don t have to go out of y...

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