I have a QSC PLX 2402 and it works great. It was considered lightweight when I bought it! If I set it on my cabs, something in it rattles horribly. This was never really a problem, because I would always my rack on a crate next to my cabs at gigs, and never really used it at home. However, in my new home studio, I really need it to be on top of my cabs, and would like to actually use it. However, it rattles like mad, even at really modest volumes. It stops if I press down on the top of the amp. Any ideas on what to do?