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“Baby Will” Valve Junior Conversion
Version 4
Build Manual
22 September 2009
2 of 36
1. Introduction
This manual contains instructions to convert an Epiphone Valve Junior guitar
amplifier to a roaring 18Watt amp modeled after the famed Marshall 1974X
circuit. The heart of it all is the “Baby Will”, a simplified version of Marshall’s
1974X amp known as the LiteIIb. The Baby Will takes the LiteIIb circuit and
conveniently lays it out in a printed circuit board, PCB, package.
This manual provides instruction for the assembly of version 2.3 of the Baby Will
circuit board. Several of the pictures or diagrams in this manual may refer to or
display a previous version of the circuit board. However, these still apply to the
current version.
To simplify things,
•
The Epiphone Valve Junior will be referred to as EVJ, and
•
The “Baby Will” 18 Watt LiteIIb PCB will be referred to as the Baby Will.
This manual guides you through the conversion which includes:
•
removing the stock EVJ chassis from its cabinet,
•
extracting the stock EVJ pcb,
•
assembling the Baby Will,
•
installation and hookup of the Baby Will into the EVJ chassis,
•
initial power-up and testing, and
•
reinstalling the chassis back into the EVJ cabinet to finish up the job.
