A frequent problem with the Blues Junior is failure of the tube circuit board. The EL84 run hot and this leads to the pads lifting away from the boards and due to stress the tracks break. We have designed our own replacement circuit board that features a durable double-sided construction and generous pad sizes to resist deterioration. Additionally it sports bias current test points to make to easier to check your tubes after a replacement.
These are available on eBay and reverb.com for £19.95 inc shipping (UK only). We also have a premium version with gold plated sockets that includes a bias adjustment trimmer mod kit for £26.95.
You can download the installation instructions here: Instructions