I've got a fender concert tube amp which belongs to a friend who lives in the UK.

It's got a problem, every time I turn the amp from standby to play, there is a bit of a popping sound. It only happens if the reverb is turned on, the sound sounds very reverby, then after a while it goes away.

I think it may be a problem with the spring reverb, or reverb tube, but I dont understand why it would only happen when I go from standby to play....

The whole amp, including reverb works fine apart from that

any thoughts?

I think the amp is from the 80s, its a 2x10" combo, looks like the tubes were replaced maybe 6 years ago, just before this guy left, then the amp wasn't used much.

I have cleaned all the connections. and fixed one of the support springs that was broken inside the spring reverb tank.

My deluxe reverb does that as well. I think it's normal. I get it both with and without reverb but it's only really audible with the reverb since it, well, reverberates.
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