Tube amp "pops" when put in standby

[rippingrudy]

Are there any particular reasons why a tube amp would make a "popping" noise when it's put into standby? None of my tube amps have ever done this but a friend's does.

Thanks

 

[stokes]

What kind of amp.It is common in old Fender amps,and other tube amps,for the standby switch to develop carbon across the contacts causing a popping sound.Changing the switch cures this.

 

[rippingrudy]

It's a Studio .22+