I am having a noise issue that I can't run down and am seeking the wisdom of the forum. I have a Dr. Z Jetta and a Boss Katana 100. When playing either my Player Series Tele or my Vantage VP795 (humbuckers), I get a crackle out of both amps on some sustained notes (open E and G are two biggies). The crackle is more intense the louder the guitar volume is turned up. The tube amp did need new preamp tubes a few weeks back, but the typical bad preamp tube noise is gone and this is something different. Straight in, through my pedal board, different cables, no change. I have a TrippLite voltage regulator with good noise filtering, so I don't think it is a power issue. I have a lot of stuff in my basement practice space (PC, Roland digital piano, dimmer lights), but turning off and unplugging those things has no effect. It almost feels like harmonic feedback, but it is an unpleasant crackle as opposed to what I'd consider typical guitar feedback. I can actually hear something rattling in my drop ceiling on those same notes that cause the crackle. The last thing I'm going to try is physically moving the amps to another spot in the house to see if that changes things. Besides trying a different room, anyone got any suggestions?