Valve amplifier repairs & testing.
Real workshop fault-finding on guitar and valve amplifiers — from bias and valve condition through to power supplies, output stages, transformers, components and PCB-level repair.
What we can check and repair.
We work at component and circuit level where practical rather than treating every fault as a board-swap exercise.
Output-valve condition, plate voltage, dissipation and bias checks where the amplifier design allows adjustment.
Rectification, reservoir/filter capacitors, dropping networks, unstable HT rails and associated faults.
Power valves, screen/grid circuits, cathode components, bias supplies and output-stage fault-finding.
Output and mains transformer checks, impedance/reference calculations and low-voltage ratio testing where appropriate.
Resistors, capacitors, semiconductors, sockets, damaged tracks, dry joints and heat-related board faults.
Crackles, drop-outs, volume instability, hum, intermittent protection and faults that only appear when warm.
In-house valve testing and bias check.
All fitted valves can be condition-tested using our Amplitrex AT1000, with output-valve bias checked and adjusted where applicable.
Outside, inside and on the bench.
These photographs are from our own repair work and show a mixture of amplifier exteriors, internal electronics, valve testing and bench diagnosis.
Need a valve or guitar amplifier repaired?
Send the make, model and fault symptoms and we’ll advise on booking it into the Telford workshop.