Product Description
Marshall JCM2000 amps when ageing tend to have the main printed circuit board start to become slightly conductive and bias to the EL34 output valves becomes unstable or goes very high and cannot be adjusted. This results in high valve anode current which cooks or wrecks the output valves.
You can read our blog on this subject for more in depth info
This kit totally fixes this issue without the need for replacing the whole main circuit board. If you know how to use a soldering iron and know how to work on a circuit board then this is an easy upgrade.
The kit consists of a little printed circuit board with full instructions and picture on how to fit the board and saves on replacing the whole main board. Some expertise in soldering is needed to install this board. If you are not sure get an amp tech to fit the board
This version is designed for the DSL series. There is a version for the TSL series too. The kits are stocked and posted from the UK.
We have used this kit in a Marshall amp ourselves and it completely solved the cooking output valves problem.
The product is supplied with the board, adhesive stand offs to mount the board, and full step by step picture and written instructions. We updated the instructions on 13th June 2018. This is not a Marshall product but is a solution that is fully proven through many folks following our instructions and successfully solving and overheating amp.
There is special drill bit needed to drill the printed circuit board and this is included with the kit. Price includes post and is sent 2nd class in the UK. There are shipping options for worldwide shipments at checkout

Fitted Board in a DSL 50 Amp