Mikey Dee Seen a few of these recently and worth sharing some problems and interesting solutions that I have found. Fender Supersonic – no sound or fading sound If your amp produces no output and the lights on the back are flashing about then you might have a faulty autobias unit. The auto bias unit fitted to … Read more
Restoration project of a 1962 Vox AC15. Clearly seen some earlier work clue being the orange drop capacitors fitted around twenty years ago. Most of the carbon composition resistors were high asnd showing signs of surface cracks so all replaced. The Mullard valves appear to be original and in fine working order. What a great … Read more
All the way back from 1941 this is got to be one of the oldest amps that I have worked on. Pair of 6L6 output power valves red chassis, lots of rust – sounds good as gold. Bit of history with this amp as it was stationed in Pearl Harbour back in the day and … Read more
Squeezebox I had the fortune to repair one of these valve compressors recently. Two 12AU7 valves, optical coupling, built to the standard of a battlefield weapons system. I was expecting it to sound good. Some compressors just seem to be so subtle that you sometimes don’t even notice them. Not so with the squeezebox in … Read more
Mackie Studio Monitors HR624 MK1 – no power or wont stay on. These great little monitors suffer from a regular power failure problem where they will not turn on. Not always, but quite often, this is actually a fault with the standby circuit which shuts the amp off as it thinks the input signal is … Read more
In electronics heat is often The enemy. In valve amplifiers there is a tension between this basic rule and the valves themselves which get mighty hot and also the established design methods for amplifiers. The problem is that heat damage caused by power resistors and valves eventually changes the circuit board material from a good … Read more
This amp, unusual with its master volume control had become unreliable. Occasional red plating, bit of noise. The cause is heat damaged circuit board. Just look at the pictures below showing the damaged sections – the dark areas indicating heat damage. The problem is that heat damage eventually changes the circuit board material from a … Read more
Post 1990 Fender amps seem to have a variety of input jacks fitted. The great American amp manufacturer seemed to have tried lots of different styles of Jack but they all have in common flakey behaviour and robustness compared with old amps from 50s to the 80s. In older amps you commonly see open jacks … Read more
If you are having trouble with any of the following boogie symptoms then I may be able to help you out as I have spent more than my fair share of time on these metallic monsters. Mesa Boogie amps are reveered by players for their unique sound. But for us Amp techs they can be … Read more
These medium sized combos from Marshall should be very cool. They are packed with features (like multiple voicings, low noise pre-amp, fab speaker) all in a small box. Unfortunately they are not so cool because they run so hot and they suffer from it. Look at the picture left. What you are looking at is … Read more
Just look at how neatly these amps are made. Neat little wires running north and south like an underground train map connected by thick copper bars. Icon Audio make a great range of valve based hifi.
Wow what a treat. This 1966 AC100 needs a service. Well after all these years yes I agree it’s about time. One owner from new, original cover and used twice weekly in the band. The sort of thing vintage amp enthusiasts dream about. This rarity is one from the erase when pop music was really … Read more