APOLLO PREAMP DRIVE MK. I
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 Apollo Preamp Drive Mk. I is an adaptation of the Catalinbread WIIO, based on the Hiwatt
amplifiers used by Pete Townshend of The Who, particularly their Live at Leeds show from February 14,
1970. (The artwork for the original pedal makes it obvious that “WIIO” is intended to resemble “WHO”.)
The WIIO was originally released in 2009 as a limited run of 100. The limited availability caused a huge
debacle as people from gear forums bought up all the preorders and flipped them for profit, capitalizing
on Catalinbread’s favored status among gear aficionados.
Catalinbread was not happy with the way the circuit turned out, so before releasing the non-limited
version, they overhauled the circuit to reduce the gain and tweak the EQ so it was more versatile as an
amp platform. Most people agree that the second version is superior, but the hype surrounding the first
version has given it a lasting reputation.
The WIIO was succeeded by the RAH, which is largely the same circuit but with a midrange knob added,
and the circuit re-voiced for Led Zeppelin’s famous show at the Royal Albert Hall. (They even referred
to the RAH as the “Royal Albert Hall Edition of the WIIO” in the manual.) The WIIO was discontinued
shortly after the release of the RAH.
The Apollo Mk. I is a direct adaptation of the V2 WIIO (non-limited version). The only modification is the
addition of a trimmer that makes a feedback resistor variable, allowing adjustments to the gain, tone
and feel of the circuit. The RAH is also available from Aion FX as the
.
USAGE
The Apollo Mk. I has the following controls:
•
Gain
controls the amount of gain coming out of the first amplifier stage.
•
Bass
and
Treble
form a 2-band tone stack adapted from the original amplifier.
•
Master
is the overall output level.
•
Feedback
(internal trimmer) controls the global feedback from the third stage back to the first. Set
it just past the halfway point for the stock circuit, and then adjust it to taste.
