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Working on a '84 JCM800 with reverb not working. Turns out it was just a bad RCA jack connection, but I sure chased my tail for a while. Rather than taking the tank out of the head chassis, I grabbed a used one of the shelf and wired it up. The drive signal was there, and I got spring noise if I touched them, but it was along with a loud sputter that went away with the reverb control. I checked the parts around the recovery triode, everything looked good. I grounded the base of the mute transistor, nothing changed. All I had to do was touch or move the tank slightly and there was a loud sputter. Wasn't making sense.
It was then I decided to check his tank, and found it did not cause this sputter sound. I cleaned and tightened up the jacks and it worked fine. I think my tank was actually producing reverb, but the sputter was so loud I couldn't turn up the control enough to really tell.
So what was I experiencing? The original tank is a 4DB3C1B, and my test tank is a 9BB2C1C with one of the three springs missing.
It was then I decided to check his tank, and found it did not cause this sputter sound. I cleaned and tightened up the jacks and it worked fine. I think my tank was actually producing reverb, but the sputter was so loud I couldn't turn up the control enough to really tell.
So what was I experiencing? The original tank is a 4DB3C1B, and my test tank is a 9BB2C1C with one of the three springs missing.
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