- Cosmic Ampworks
®
- The Ultimate Harley Benton GA15 Mod Kit- Version 1.4 - 200127
© 2020 -
1
Dedicated to the Advancement of Stellar Tone!
Dear Customer,
Thank you for your interest in our Harley Benton GA 15 Ultimate Mod Kit!
Successfully implementing the modifications described in this manual will transform your GA-15 from an ugly
duckling among guitar amplifiers into the metaphorical swan
–
a great sounding tube amp! Hopefully, it will be
an enjoyable process too
–
the journey is the destination :)
Please be aware that some of the mods may be quite challenging to perform. Improper implementation of the
described changes may render your GA15 unusable and can even be dangerous! Opening up and changing
your GA15 is entirely for your own risk and should only be done by properly trained personnel. The
modifications described in this manual do not necessarily comply with any electronic safety standards.
Disclaimer: Cosmic Ampworks
®
assumes or undertakes NO LIABILITY for any damage suffered as a result of
the use, misuse or reliance on the information and content in this manual.
Figure 1. Modified Harley Benton GA15.
1. About the mods
The mods are described on our webpage (
https://cosmicampworks.com/harley-benton-ga15-guitar-
). In the current manual, they have been re-arranged in order of increasing
complexity. So, before diving into the deep, there is still some room for learning by doing. It is advisable to
implement the mods one-by-one, and checking carefully whether your amp is still functioning properly after
each mod, before proceeding. D
on’t forget to listen to the sonic
changes along the way! The manual starts out
with some pretty straightforward tweaks:
