Major Feedback Whiny Sound Coming From Amp with certain guitars

[jauernis]

So I used a PRS and a Gibson V last night through a windsor/mesa cab and tremoverb/mesa cab (all at different times)

The PRS guitar doesnt have any feedback at all on all amps. The Gibson V is giving a whiny loud feedback on both amps as well as the gibson explorer I tried. Thought it was the tubes but its not because the windsor is brand new and no feedback with the PRS guitar.

Any ideas what might be causing this?? And how to resolve this?

 

[arv_foh]

does the feedback stop when you wiggle the cable in the input jack

 

[Sweetnothing]

Wiring/microphonic pickups could cause that, are the pickups on the V stock?

 

[Sloan]

I would still check preamp tubes. swap them around and see what happens.