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112 RD fifty build date 1981

Hello and thank you. I bought this amp new in 1981 and have been using it every since. Never had a problem before.

Just today, cut out twice in rehearsal .

I was on limiter side. Switched to clean channel, rotated volume control and came back on suddenly. That worked both times.

I am not a tech - any suggestions are much appreciated! Thanks!


Try This

Some things to try from least to most invasive. Turn off your amp and unplug it before starting.

First, check that your tubes are securely seated, and your speaker cable is firmly attached to the speaker lugs and fully plugged into the Speaker jack. Vibration from playing can make strange things happen with loose tubes or speaker lug connections.

Next get some electronics cleaner spray (DeOxit, CRC QD, etc.) and spray the small openings at the top and bottom of the Clean/Limiter rocker. Do the Power toggle switch too, and all jacks front and rear. Work the switches vigorously at least ten times, plug and unplug a cable jack plug the jacks as well.

If that doesn't resolve the issue, or your are feeling a bit more adventurous, undo the chassis bolts and pull the chassis. Spray electronics cleaner into each control pot, rotating the pot vigorously a number of times.

Worst case you have a bad solder joint or broken component connection somewhere. In which case you, or a tech will have to locate and repair.


Thank you so much, inertian.

Thank you so much, inertian.

First thing I discovered was one of the power tubes was not firmly seated. Remedied that as well as checked speaker cable connections (all good), used DeOxit on all plugs and Clean/Limiter rocker.

Turned on and played for about 30 minutes with no issue. Yesterday was happening every 2 or 3 minutes or so. I assume it was the power tube not being fully seated. My mind immediately runs to " my amp is fried" as opposed to simple first.

Thanks again! Very much appreciated!

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