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Feedback issues with GA42RVT

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I have a GA42RVT 2x12 combo that I absoluately love. The only problem is that the amp feeds back very easily, even at low-moderate volume levels. This is especially true in Channel 1, particularly with the treble turned up. In fact, maxing the treble on Channel 1 produces a immediate (and loud) squeal. Anyone else having this problem? Any advice?? Thanks!

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I know this one!(maybe!)


I have an '82 Marshal 12 watt solid state that did the same thing. I noticed scratchiness through the speaker when I turned the knobs. I went to Radio Shack and bought a spray can of POT lube/cleaner and opened her up.

Spray a burst or two through any opening on your pots and rotate them, then spray again to flush. It fixed mine.

If this is a tube amp(I am not familiar with it), then one or more of your tubes may have gone microphonic. If this is the case, the tube re-introduces the output from the speakers into the signal path causing your textbook feedback loop.

Warm it up, then GENTLY! tap your tubes one at a time with a pencil. if you hear it in the speakers, then that is most likely your problem.



I hope this helps you,



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