Will Replacing stock marshall tubes for Tugsuls or JJ's along with power tubes Reduce High volume squeeling?
Framus Cobra
Marshall JCM 900
peavey 5150

Mesa 4x12
I would think that would be more of an eq or pickup issue (as said.) Might want to invest in a premium cord just in case.
VERY doubtful it is the tubes
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stock marshalls are microphonic. they're just rebranded Sovteks.

I got Tungsol 12AX7s, and JJ/Tesla EL84s in my amp, I crank it and get no feedback 5 yards away.

I was getting feedback from 5 yards away with the master volume at 4. now, i don't have to worry about it.

but I can still get intentional feedback and harmonic feedback if I want to.
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