Hey guys, lately my SVT3 has started to make these weird *scratching* noises, even when the mute switch is engaged. Tonally any playing through it sounds the same as it always has, apart from the scratching. I want to say that I think it's an issue with dirty power or something, as I'm not long in a new house, but I have used it here before and not noticed anything strange. It wasn't doing it when I last used it at a friends house, so I'm worried it got shaken up in the car or something? Could it be a tube issue? I think not due to it sounding the same, but I'm far from an expert. Unfortunately I don't have an interface at home right now (nor do I own a PA) so I can't test the DI. Increasing the volume or gain does not seem to make any difference, as expected I guess since it still does it on mute. Any ideas?