EQUINOX AMP OVERDRIVE
2
TABLE OF CONTENTS
1
Project Overview
7
Drill Template
2
Introduction & Usage
8
Enclosure Layout
3-4
Parts List
9
Wiring Diagram
5
Build Notes
10
Licensing
6
Schematic
10
Document Revisions
INTRODUCTION
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.
USAGE
The Equinox has the following controls:
•
Treble
,
Mid
and
Bass
form a passive 3-band tone control for flexible tone shaping.
•
Gain
controls the amount of gain in the op-amp gain stages that is fed into the clipping stage.
•
Volume
controls the overall output of the effect.
•
Clipping
(toggle switch) selects the clipping diodes which changes the character of the drive tone.
