Hello everybody? I'm looking to try to figure this issue that I am having. Ok so when I am playing my guitar I am noticing a fluctuating 20% drop in volume and then a short swell back to the original volume that is preset to the assigned channel. I AM NOT CHANGING MY PRESET. This is occuring in the middle of playing on the same channel. Now this hasn't just happened with my HD PRO unit. This also occurred with my Spider Valve HD 150. I've tried a million different things to correct this like change my cords and check input jack connections as well as changing tubes and restoring the amps to their respective manufacturers defaults. Nothing has fixed this. The only other thing that I can think of is that the wiring in my home may have something to do with this issue since it is the only other constant. Your thoughts on this community???????