Danuman Posted May 22, 2017 Share Posted May 22, 2017 (edited) Sorry, if this is in the wrong section, but I was hoping some of you might shed some light on my predicament. This weekend I was playing an outdoor gig with my reissue Deluxe Reverb, when about halfway of the third song of the first set my sound started cutting out. When I checked round back I noticed one of the power tubes looked like it was just about ready to go pop. I turned it off immediately. I had changed some of the 12ax7's a couple days before, so I had some spares, which I then put back in, and I was able to finish the night on the other channel (V1). Lovely gig, too. Unfortunately it then turned out somebody had keyed all of the band's cars, which were parked around back. One of those nights, huh. After some testing today, I found that my amp really doesn't sound healthy. The guitar sound is fine, but after a couple of minutes it starts to make a sort of gurgling sound. Anybody got any ideas what might cause these symptoms, and - more importantly - how to make it go away? I fear it might not be the tubes themselves... Thanks for looking! Edited May 22, 2017 by Danuman Quote Link to comment Share on other sites More sharing options...
Beer of the Bass Posted May 22, 2017 Share Posted May 22, 2017 (edited) If you have one red-plating power valve, swapping the position of the two power valves could help you identify the problem. If the same one red-plates in either socket, you probably need new power valves. If either valve red-plates in the same socket, it's more likely to be another issue with the amp. But don't run it like that for longer than you need to. Edited May 22, 2017 by Beer of the Bass Quote Link to comment Share on other sites More sharing options...
Danuman Posted May 22, 2017 Author Share Posted May 22, 2017 Thanks, that's a great tip! I'll give that a try asap. Quote Link to comment Share on other sites More sharing options...
Danuman Posted May 27, 2017 Author Share Posted May 27, 2017 Luckily I kept a few old 6v6 tubes in a drawer. Switched 'em around, and fortunately the problem went away. Whew, I guess you can never be too prepared with tube amps. I'll be bringing those spares with me from now on. Here's hoping it was circumstances and not some or other drifting component elsewhere in the amp. Quote Link to comment Share on other sites More sharing options...
Beer of the Bass Posted May 27, 2017 Share Posted May 27, 2017 (edited) It would be a good idea to have somebody check the bias if you've changed the 6v6 power valves. It's a quick job for any amp tech and they should be able to check there's nothing else amiss, if you're worried about that. Edited May 27, 2017 by Beer of the Bass Quote Link to comment Share on other sites More sharing options...
Danuman Posted May 27, 2017 Author Share Posted May 27, 2017 Cheers, that's good advice. I have some gear to measure them myself, but when I last checked these tubes, they were running 21.5ma or thereabouts, so for the time being I guess they should be OK. I'm going to swap them out for a new set before too long anyway, so I'll think about taking it to somebody more knowledgeable then. Quote Link to comment Share on other sites More sharing options...
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