I used to have an LC30R, and i never had the reverb problem-i just found it was very sensitive- 3/10 was the most reverb i ever needed, after that it became quite peculiar sounding. The whoosing static-i sometimes got it, sometimes didnt, usually when it was cranked past 7 (which was enough gain for pretty much every use). I just turned it off and on again, and it always seemed to disappear. Youve probably tried that though, so I'd go with pawel-it could be a wierd wiring in your house, or just the amp being to close to another power source.