I've notice some weird noise comimg out of my royal atlantic. It happens on higher gain settings. Of course there's the regular amp hiss and hum. If notice some kind of rattling on higher gain settings with higher output pickups (humbuckers). The weird thing is that it happens only when im in from of the amp...even at 10 feet. On the side....no rattling. Even with the guitar volume at 0 the rattling is there. My noise gate cuts the regular hiss and hum but not that rattle...help please.