I bought NOS EL84s for my Laney VC30 but when I plugged them in they went pop. Wassup?
John from Champ Electronics in Nottingham (see Links) reminded me of this one. The sockets in the VC30 are wired up to accept only one type of EL84. They use a pin that has no connection on some valves as part of the circuit – however other EL84s do have a connection there – and pop they go when you plug them in. Not too hard to rewire the sockets if you have this problem. The advice is to get this job done before plugging in any new power valves except those Laney supply. While we’re on the subject, John pointed out another issue on a VC30 he had in. He’d sorted the wiring thing, but still found that one of the power valves glowed red on the plates however many times he checked the bias. Then he noticed it was very close to the speaker magnet. The magnetic field was helping the current flow, overheating the valve. Well spotted John. Tricky little amps, VC30s.
