So I've had my DSL40C or a few months now, probably around 4 or 5 months, and just this week is has started making loud popping and crackling sounds when it's on and when it does the volume either gets quieter or louder. It has gotten worse and worse as the week went on. First it was just one pop per session but now it's almost unusable how much it pops and interferes with playing. I have no experience with electronics or amps or tubes or whatever so I don't know how to fix it or what the problem could be. What should I do to fix it? Any help is appreciated. Thanks!