CHAMP ELECTRONICS -" THE VINTAGE VALVE AMP HOSPITAL"

NOTTINGHAM, ENGLAND

 

REPAIRING A JOHNSON / VAMPOWER 100 watt AMPLIFIER HEAD







This is a “Johnson branded” (VamPower) MK1 head.






Note the two odd pairs of output tubes, and the two on the right also looking pretty sad!






Some work had previously been carried out on this one…..especially on the power supply & bias board.






The output drive stage board removed and stripped of all the duff crap, plus chemically cleaned too.






Underside of same board…….also chemically cleaned too.






All the replaced components fitted.







The repaired output board back in place.







It is really ironic that virtually all the VamPower products that I have worked on (Triumph Electronics) seem to have troublesome in/out sockets. Here……again…….is a new full-set of output jacks!







With the same thing applying to the input jack sockets too?






The pre-amp/drive board out for servicing. This had me foxed for quite a while until I eventually found a hair-line crack in one of the tracks! Bloody cheap-tack PCB’s!






All finished and chemically cleaned too.







Just look at the dreadful hardware/metalwork on these. They were all pretty much like this but the prospective customer would have never seen this in the shop window with a new gleaming amp!






Most things finished and back in place here. However the front panel is still off as I was tracing & drawing the schematic at this point. To view this CLICK HERE.






Everything pretty much finished and back in place here.






New full-set of output tubes, and everything is now cool!







 

And..............an email received from Lewis, the amp's owner:

"Alright John? 

The Johnson is f*****g brilliant! Cannot believe the difference in it. Before, when I used the bite control, it would go all ear splitting and horrible. Now it's a really heavy grind. The clean is also really bloody good - easily as good as my band-mates twin - and dead quiet too. We're gonna do a lot of catch-up practice/recording with it next week. The tone controls seem a lot more useable as well. Worth every penny!

Regards, Lewis."

 

 


 

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