"I am pretty sure the buzzing/vibrating originates from the sub because if I press on the back amplifier panel near the high level in (top right), the buzzing almost completely stops."

you put the finger very near the source of the problem, now you need to put it at the exact spot, figuratively.

See: http://www.blu-ray.com/community/gallery.php?member=Gelli
or: Axiom Gallery