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TH30 intermittent cut-out

Posted: Mon Aug 27, 2018 8:37 am
by Scholesy
My second hand TH30 quite randomly decides to emit a loud noise that sort of sounded like when you touch the end of your instrument cable, only worse. I plug into it later and it works for sometimes hours, sometimes just minutes, then decides to cut out and does the same thing. I just plugged back into it and it did it again. No guitar signal is coming out at all. It just replaces my guitar with the horrible noise almost as if a fader knob is being turned up. It stops making the noise in standby, and starts right back up in full and half. It also does it in clean.

I have checked it with multiple guitars, instrument cables, cabinets, and speaker cables.

All four tubes are lit up...they are stock tubes and will be old. A matched set of all 7 tubes are on the way...

Any help would be greatly appreciated.
Thanks so much in advance!

Re: TH30 intermittent cut-out

Posted: Mon Aug 27, 2018 10:00 am
by Les Paul Lover
If it does it on the clean and dirty channel, I bet one or more of your power valves have gone bad.

Refrain from switching it on until you've replaced them all. Worst case scenario, and bad power valve can take out a few components (rare) and blow the fuse (common), which is just extra hassle.

Replace all EL84, and I bet your issue will be gone.

Re: TH30 intermittent cut-out

Posted: Thu Sep 06, 2018 3:55 am
by robbvant
ya man, id retube all JJ's, preamp too while your in there. I just did it on mine under $100 amazon prime, 1 day shipping, good luck. you wont need it, its very simple.