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[PK1]

My '71 Vibrolux Reverb quit working. It was working fine then I had set the guitar down for about 10 min and when I picked it up there was almost no volume. I could just barely hear it. Turning up the volume produced a slightly louder but very flabby sound.

I plugged the guitar, using the same cord, into another amp and that worked OK. Eliminating the cord/guitar as the problem. I plugged in another speaker but that didn't help. The problem is common to both channels and all four input jacks. I pulled and reinserted the reverb tank cables. The tone controls are not zeroed. The speaker is plugged into the correct jack.

I swapped out the tubes one by one but that didn't solve the problem. Next I pulled the chassis and looked around inside, including looking at the large power caps, but nothing caught my eye. Everything "looked" fine, no caps had external leaks.

I checked the voltages at a couple locations and found they didn't match what the schematic called for. Using my old Realistic analog VOM, I read +490v off pin 8 of the 5U4GB rectifier socket instead of the +468v called out on the schematic. Also I got +405v at pin 4 of both 6L6's instead of +455v.

I don't know enough to tackle troubleshooting/repairing an amp so it will have to go to a repair shop. However, I wonder if anyone as any ideas what the problem might be. The amp was re-capped some 20 years ago so that should be done again.

Anyone know of a good tech in the Claremont/Ontario/Pomona Calif area? I check Ted Weber's list but am looking any other suggestions.