I have the 100w Badlander and it's a bad ass amp no doubt. Had it since new since inception, about 5 years now. Never had an issue till now. The other night experienced volume swells and thought it was a loose guitar lead. It wasn't. Thought it was a flat battery in the active guitar. It wasn't. Could it be one of the power valves EL34 is on it's way out? Any ideas? I do have spare 6L6 set, I could always swap em out then try. If it still happens, what else could it be? Appreciate your thoughts, suggestions and comments. Thanks folks! JJ