guitar amp service

Amplifier Service

My name is Tim Evans and as a guitar player myself guitar amps are my passion.
Since graduating from RMIT near on 30 years ago I have designed and built many guitar amps for Labsystems and serviced thousands of every make and model, I did warranty repair for Fender and Peavey for about 20 years. "What a great job I have".
When I repair or service an amp it will be done properly!
The last test after the work is done, the Les paul or the Strat in the studio.

As a guitar player myself I know how an Amplifier can make or break your playing.
A good Amp, well serviced and set up is an essential tool of the trade.
If you run a Valve Amp you will need it serviced on a regular basis. Output tubes will need to be replaced about every 12 months. "Bias" every body talks About it so what is it?
Bias Voltage is applied to the control Grid of the Output Valves this reduces the Anode current@idol (no signal in).
In most Guitar Amps say Fender Twin or Marshall 100w Head the output stage is class
AB very nearly classB, this means the output stage of push pull type where the sound waveform is split 180degrees by the Phase Splitter then fed to the Output Valves and joins back together in the Output Transformer, thus we get a full waveform to the speakers.
Half the Output Tubes conduct through the positive cycle the other half the negative cycle.
If the Bias is not correct say "over Biased" we get crossover distortion, If on the other hand
we under Bias the Valves will run hot and not last as long or detroy themselves and sometimes the Amp.
Will Bias change the sound ? "yes!" Thats why you need to get it set up properly with the correct gear and knowledge to do the job!