Marshall TSL Bias Mod
Our Marshall TSL Bias Mod kit is for Marshall JCM2000 TSL amps. As the printed board ages, it becomes slightly conductive. This interferes with the bias circuit on the EL34 output valves. The output valves overheat and the bias cannot be adjusted to a stable value. El34 life is then greatly reduced
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. Some expertise in soldering is needed to install this board. If you are not sure get an amp tech to fit the board
This Marshall JCM2000 kit consists of a little printed circuit board with full instructions and picture on how to fit the road and saves on replacing the whole main board.
This version is designed for the TSL series. There is a version for the Marshall JCM2000 DSL series too. The kits are assembled, stocked, and posted from the UK.
We have fitted 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. This is not an official Marshall kit but was developed to solve a common issue with this amp series.
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 1st class post in the UK. We ship this kit worldwide and you can select your shipping option at checkout
The manual was last updated in July 2020.
We can send you a link to the manual so you can review before deciding to purchase. Just email us and we cn send you a link to the document
You should consider replacing your EL34’s as they will likely be worn due to overheating. Check out our EL34 matched pairs and quads from JJ, EHX, Tung Sol