Put those anti tube rattling thingies on them and they're fine.
A well made combo does not have that problem.
But yeah some are bad.
Every combo does it. I hear from a lot of players who say they don't have this problem. Maybe they're lucky. I hear from others who say the same thing I'm saying right here.
no I didn't contradict myself JeffB, but let me try to be more clear. Every combo I have plugged into does the jingle bells. I also said other players don't have the problem, and I said maybe they are lucky. If I played your combos I would get jingle bells. I would hand the guitar back, and maybe you would not get jingle bells. There are reasons for that, too.
Dr. Z amps are built very well. I meant old Fenders too. All combos, in fact.
My Jet city doesn't have that issue.
If ALL the combos YOU play have that issue then YOU shouldn't own a combo.
Different strokes and such..........