I've had this amp for several years now, and only since last September have I been gigging with it. Recently, it's started to make a horrible 'pop' sound whenever I switch between OD2 and Clean; the only way I've found to get rid of this is to reduce the gain on that channel substantially, which defeats the object of using that channel in the first place

My first thoughts were that it could be the footswitch (I lost the original one at the end of January and have since acquired a replacement), but the same problem arose when I switched between channels on the amp itself. Could it be that one of the tubes is on it's way out, since I've not replaced them in the whole time I've had the amp?

if I am not mistaken, I believe that amp only has 1 tube.
I dont know, that tube may be dying. I'm no tube expert.

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It's unlikely that the preamp tube would cause that symptom. It might just be that the switch damping mechanism is beat and you need a new switch. I would see if they have a forum on the Marshall site since this is likely a common failure.

i doubt it would be the tube... that tube isnt really doing much in the amp... it's not even a true all tube preamp... just a s.s. one with a tube in it for extra gain.

your first problem imo was buying an avt.

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