Technical information

Introduction
Welcome to the step-by-step instructions for the Metroamp 100 Watt Master Volume
amp kit. We hope you will enjoy building your amp and will learn a thing or two about
tube amps in the process.
The purpose of this kit is to replicate the Marshall model # 2203 JMP amps produced
from 1976 until 1980. The first Marshall amps to feature a master volume control,
cascaded preamp channels, rocker switches and large 11” Marshall logo.
1979 Marshall 2203
These amps are, in my opinion, THE workhorse 100W amp for rock music. But they also
cover many other styles gracefully. These amps are also ideal for modification. Anything
from a minor tweak to an over-the-top multi-channel, high gain transformation.
We have taken great care to re-create many nuances and details of the original Marshall
2203, but there are a few notable exceptions, each with a specific purpose. Most
notably, our use of a point-to-point terminal board vs. the original PC board. This is to
accommodate larger, discreet components and to allow easy tweaking of the circuit. We
also manufacture our steel chassis to use modern style impedance and voltage selector
switches, which are more reliable than their vintage counterparts.
This kit also features more options than any other Metroamp kit. Each builder has their
choice of several available options:
• Mercury Magnetics or Metroamp brand transformers
• EL34 or 6550 output tubes (both types were found stock on original 2203’s)
• Optional ZERO LOSS FX loop™
• Any of our tweaked 2203 mod options
Enjoy your kit experience and feel free to contact us with any questions or concerns at:
[e-mail]
Tech support and lots of technical information are available in our online forum and wiki.
Visit the forum at: http://www.metroamp.com/forum
And the wiki at: http://www.metroamp.com/wiki