If you’ve read our earlier story on the Harley Benton GA15, then you know that we’ve developed something we like to call “the Ultimate GA15 Mod Kit” – simply because you can’t go any further in modifying a GA15 and still call it a GA15. The 27-page PDF manual that exactly describes how to implement those mods can now be viewed below. Depending on the speed of your internet connection, it may take a while to load because of its file size.
In the step-by-step manual, modifications are arranged in order of increasing complexity so that, before diving into the deep, there is some room for learning along the way. You can find a list of the required parts on page 6. We supply sets of carefully selected parts and an optional full-color printout of the manual as a complete “Mod Kit” via our web shop, potentially saving you a lot of hassle. A more elaborate description of the modifications can be found in the previous post on the GA15 or in the manual below. We hope you’ll obtain great results and have a lot of fun working on your GA15, but before starting out, please refer to the safety advice in the manual and to disclaimer below!
Disclaimer: We strongly recommend you to have a qualified amp technician modify your amp if you have not been trained to work with high voltages. A tube amplifier chassis contains lethal high voltages even when unplugged – sometimes over 500 volts DC! 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. The modifications described in this manual do not necessarily comply with any electronic safety standards.