Unfortunately we’ve seen far too many where the user has changed the output valves and because the amp is known as ‘fixed bias’ think they can just change out without any readjustment because there is no adjustment..
Ever Fender Blues Junior we’ve seen through the door has a biasing set at between 30% and 60% higher than the Nominal setpoint that valves are usually biased to based upon plate voltage and power using ohms law.
We would advise that this is carried out by an experienced person such as ourselves due to the high voltages present on the PCB. There is also a very high chance of damaging the output valves and possibly transformers if the mod isn’t carried out correct or you short out a solder pad.
For the price of a standard service and around £6 worth of parts we can carry out a service to check for any existing damage, check the valves, Deoxit cleaner the pots and carry out the bias mod.
A full MOT for your blues junior and a better environment for your valves to run in!
Repairs currently are running on time for parts we keep in stock.
Some of our distributors are closed adding to a slight delay.