A little amp with three valves - EZ80 for the rectifier, ECC83 for the preamp and an EL84 for the output section.

The amp came in for a service. We found a dodgy pre-amp valve and the bias was very hot on the EL84.

A new valve and a new cathode resistor means a much happier amp. Getting the bias right will extend the life of the EL84 which looks original.

The tone pot didn’t seem to do much and so we changed the valvue of the capacitor and now a gentle roll off of high frequencies. The amp sound great but to my ears maybe needs a little more high end. Will make a lovely addition to a collection.