I had to repair a Gibson Les Paul boost circuit and drew out the diagram which does not seem to be available on the net so I thought I’d share. The 47k trimmer sets the boost gain. The 4.7pF caps are an educated guess. I think they are just there to avoid RF interference. It was odd but the source terminal of the J202 FET was connected to the 22k load resistor R3. I guess they are interchangeable.
I had a Fender Rhodes 54 key electric piano in for repair last month. They use guitar type magnetic pickups wired together. If one pickup fails, every key goes silent. It is still easy to get spare parts for these so they can be brought back to top condition. The 73 or 88 key versions are more popular than this 1980 vintage 54 key instrument. I repaired or replaced 17 pickups on this one, re-adjusted the hammer action and individual note volume and re-tuned. Call me if you have one needs some attention.
I think this is the most powerful tube bass amp on the market at the moment with eight Svetlana Winged C 6550 power tubes. This one belongs to Den Davis owner of MCC Global Entertainments studio in Mottram.
Most modern small venue mixers are constructed onto a single printed circuit board (PCB). To do any work on them I have to remove every knob and nut (Too many knobs and nuts, like a gay night club). That’s an hours labour before I even get to find the fault and fix it.
I used to burn the midnight hours coding computer programs. This bracken fern style picture is generated by a fractal generator I wrote from scratch. I think the program got deleted (probably on a non-readable floppy disk somewhere!). The fractal was generated in monochrome at a very high resolution then each pixels intensity was set by the number of hits within its bounds. I then gave it a green tinge.
Fuck all to do with amp repairs though!
Tony from Oldham’s ‘A Band Of Gypsies’ (ABOG Reverb Nation and on North west bands) had some work done on his Marshall DSL 50. He didn’t like the fist pair of EL34’s I put in so I changed them for a pair of pricey but highly praised Svetlana Winged C’s. They were Hot running high gain selected tubes for that bluesy compressed late break up.
I also fixed a couple of Marshall 4×12 cabs for Tony. The jack socket switch contacts always go on them so I replace them with Neutrik gold plated jobbies that should last a bit longer.
In July I had a visit from local prog rock artist John Graham of the band Ontofield (see www.ontofield.com). His Blackstar needed a couple of new tubes.
Dan’s Amp Surgery
Doctor Dan’s Power-amp Pitstop
Doctor Davenport’s Noise Clinic
Nurse Davenports Tubetastic Sound Shop
Dark Peak Electronics Workshop
Dark Peak Vaults