If you "can pretty much chopstick anything under the hood and make it do it" then there is something there that you can eventually find and fix. Tubes aren't the only culprits. Caps and even coax wiring can be microphonic. If it's a cap then gluing everything down could potentially make make the problem worse or harder to find. I suggest you keep looking for the root cause rather than work on a cover up fix. Maybe give it a rest then poke around inside again later.