Matamp Quasar 500 and Laney VH100R guts


Showed up set to bridge mode, had to open it and find the switch. Turns out not on the side with the diagram. Do spot a toasty looking resistor bottom left though. Still tested right, luckily as it was missing a stripe.



Right side this time, showing the classic K135 and J50 mosfets. Hand marked bridge/stereo switch on the pcb to the left.

Other thing:


Laney VH100R, made a bunch of noises and blew a fuse.


A shorted power valve, a miles out of spec (like, measured a couple of meg rather than open) grid resistor. Suspect someone tried a ‘fix’ by swapping positions before selling this as ‘working’. Couple of dud pres too.


Bugera 6262 Infinium Guts. 5150 MKII clone

Bought dead on ebay, to have a look at. Turned out it was just bunch of dead preamp valve, guy had reloaded it with JJs and they died after estimated 50 hours use.


Front of it, 5150 MKI style, but reverb option.


Random tested parts box valves I stuffed in, the Infinium sorts out the bias for them. Works fine by ear, not sure sticking a probe in won’t interfere with its function, so didn’t.


Inside, the infinium part is the board on the back of the chassis with bunch of push connectors. Small board with ribbon cable is the reverb. Modular inside, would guess lots of stuff in common with other models in the line.


Clsoer shot of the small modular boards, along with showing that the main circuit is pretty normal through hole pcb, not mystical magic that cannot be fixed like is often claimed about these amps. Ribbon cable is data from digital reverb.

Burman Pro502 guts, somewhat modified.


Even the flightcase didn’t save this one from UPS. Chassis is loose, the bolts pulled right through the sleeve, and the rivnuts broken loose, meaning the bolts just spin but are retained. Had to push them all the way thorough the sleeve, then address the oversized holes later.


New transformer in there and the reverb connector is removed and replaced with an XLR on the back presumably for an external unit.


Another view of the guts, showing the wiring for new transformer. No HT fuse in these puts the PT at risk.


Other end of the chassis.


Detail of the reverb mod. Now I’m thinking maybe a DIN rather than XLR but I put it back in flightcase and put stuff on top waiting for a rivnut tool showing up.