Home Guides and Fixes for Amps and Pianos

Please note: our workshop is now closed for Christmas and will reopen on Tuesday 6th January 2026. You can still make enquiries via our website.

Guides and information for Valves, Amplifiers and Pianos

We’ve compiles some guides to help you understand faults in guitar amps and pianos, as well as some fixes you may find useful.

Amplifier Information

Inside a valve

What is a microphonic valve, is it bad and how to identify.

Valve glass envelope damage from over bias

My valves glow orange, that means they’re ok right?

Gallien krueger solid state amplifier inside

The protect light has come on or the sound doesn’t come out

Crackling pot cause, inside track damage

Crackly knobs, volume jumping erratically fix and cause

Common Repairs

Piano & Synth Information

Korg updating pcb fix

Korg M50 freezing or failing to boot, updating panel error

Close up of rubber membrane contact in keyboard

My keyboard has keys louder than others?