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The heater in one of the EL34s in my JCM2000 isn't coming on. I've measured 6.9VAC between pins 2 and 7 (measuring on the tube side of the socket), swapped out tubes, and it's the socket, not the tube. Am I missing something? What else could it be?
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Loose or broken tube socket.Education is what you're left with after you have forgotten what you have learned. -
^^^^ Or cold solder joint,try reheating.KBComment
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That's what I was thinking too, but the fact that I can stick my probes in the holes and get the correct voltage threw me off. Is it likely that the socket is broken in such a way that the tube pin isn't making connection, but the contacts are still hot?Comment
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Yes, sticking the probes in is like making a solder contact so you are hitting on a good part but the socket pin is on a cold solder joint or as Enzo said it could be broken and the meter lead just happened to hit on the good side.KBComment
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I'm sticking the probe in the socket though, not on the solder joint.Comment
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The tube pins may not be contacting the sockets well enough. Try tightening the sockets by bending the contacts inwards with a small sharp scribe tool, or small pin. I always use the "pointy" edge of a utility razor blade. It will make sense if you look at where the tube goes in.
Good luck.Comment
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Hey got it, thanks!Comment
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Oh, and please unplug the amp first, and make sure all voltages are released before working on ANY AMP. Amps still carry LETHAL charges even after unplugged, so be careful!Comment
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How did you fix??Comment
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I am taking it that he retensioned the sockets.Comment
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Or just had a tube with open heater.....or bad solder on the tube pins.....The farmer takes a wife, the barber takes a pole....Comment
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