Category Archives: Amp repair

Two Marshall JCM900 Amps Repaired At JPF Amps

Here are a couple of Marshall JCM900s guitar amplifiers we’ve had in our workshop for repair in the last few weeks.     The one on the bottom simply need new output jack. Unfortunately the one on the top needed a new mains transformer and power valves, a significantly more expensive repair. These are original early 90’s amps, […]

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Orange Crush 15R & 30R Guitar Amp Repair

Here’s some photos from a pair of Orange Crush guitar amps I’ve had in for repair: a 15R and a 30R. Both had a very loud hum when the amp was at idle. In a solid state amp this is almost always due to poor power supply filtering. and further inspection showed that this was caused […]

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Peavey ValveKing 100 Guitar Amp Repair

Peavey have earned a reputation for making well-engineered amps at reasonable prices, so I was not expecting any major issues when I took in a ValveKing 100 for repair. The symptoms where that the amp was not powering up: neither the indicator light, nor the valve heaters where illuminated. This fault is usually due to […]

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Fender Hot Rod Deluxe Guitar Amp Repair: New Filter Caps.

Here’s Fender Hot Rod Deluxe that came into our workshop in need of new filter caps. Whilst you would expect the filter caps in, say, a 40 year old Fender Twin Reverb to need changing, it’s surprising that the caps in a 10 year-old Hot Rod Deluxe should have expired; however from my own experiences, […]

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Fender Blues Junior Guitar Amp Repair

I see quite a few Fender Blues Juniors in the workshop for repair; not that they are unusually unreliable, it’s just there are a lot of them out there! However you do see many of the same faults occurring, so here’s some photos highlighting these from a recent repair. Firstly, like many amps that use […]

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Aguilar AG500 Bass Amp Repair: Man vs SMD Round 1

Here’s a repair I conducted on a more modern amp, a Aguilar AG500 bass guitar amplifier, where we were dealing with the dreaded SMDs. This amp is quite an interesting design as it has a class D output stage, however unlike most class D amps it’s not ultra light. It employs a linear power supply […]

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VOX Night Train Guitar Amplifier Repair

Here’s some photo’s from a recent repair of a VOX Night Train amplifier. The amplifier was producing no sound. Curiously the HT voltage on the first pre-amp valve was only 95 VDC, way below spec. I removed the valves and the HT on the first valve stage was still only 95 VDC. On further investigation […]

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Peavey Classic 30 Guitar Amplifier Repair

Here are some photos from the inside of a Peavey Classic 30 that I recently repaired. The amp was brought in making a ton of crackling noises and was cutting out intermittently. It had been looked at previously by someone who had concluded that the PCB had absorbed moisture (not possible), and had tried to […]

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More safety earthing issues. VOX AC30 and Yamaha PA

A couple of safety earthing issues I’ve seen over the last few weeks. Here’s the safety earth from a recent repair on a JMI era VOX AC30. Suffice to say, if you were going to solder the safety earth to something, then the chassis might have been a better bet…… OK, that was a vintage […]

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Brighton Guitar Workshop website now active

I’ve posted previously that a friend of mine, Nathan, is building and repairing guitars in Brighton. Nathan’s now got his web-site, Brighton Guitar Workshop,  up and running so you can check out his work.    

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