My tube amp pops loudly when turned off?

Question

Hi guys! I've been around a few tube amps, and none of them pop quite as loudly when switched off as the one I've got.

What causes a tube amp to make a pop when turned off anyway? Stored electricity being released into the speaker? More importantly, does it hurt my amplifier when it does this? It does it even if all the k***s are on zero.

Answer 1

It is fairly common for a tube amp to do this, and some solid state amps do also.  It certainly does not harm the amp.  It is a little hard on the speaker if it is real loud.

A tube amp will have an output transformer, so this means no DC will pass to the speakers, but a transient in any stage of the amplifier will pass through to the speakers.  There are a number of causes.  A bad tube is the first possibility, and it can be any tube in the amp.  An intermittent electrolitic capacitor would be the second place to look.

I could tell you how to track this down, but we would have to do that by email.