Mesa Boogie DC-5 "Pop" Sound on channel change... tubes???

[KATFishing]

Hi - I have a Mesa Boogie DC-5 combo that I bought in the mid 90s. When I change channels either from the foot switch or the switch on the amp there is a loud pop sound from the speaker. I tipped the amp forward and watched the tubes and one of the power tubes slightly flickers when I change channels. Is this likely the culprit? I don't have any other noises (i.e., hissing, humming, static, etc.), only the pop sound when changing channels. The power tubes were changed once back in the 90s when I was part of a band, but I remember that "pop" sound happening at the time I quit playing out. It was really prominent through the PA. All these years later, I'd like to finally fix it and restore my amp. Please share any thoughts or advice. I know I can take it in, but if it's likely a tube problem versus something with the channel switch (remind you, it's both from foot switch and switch on face of amp), I can save myself the expense and just replace tubes. Thanks!!!

[mesaboogie6L6]

Same thing was wrong with my DC-5 head, I sent it to Mesa to get fixed and they sent it back to me, nothing was different, the popping noise was still there, Rich Duvall from Mesa told me it's just the way the circuit works, and it can't be fixed, so I sold it.

Good luck