Mark IV popping sound

[gibbycustom]

When I power up my mark I always do as instructed in the manual...full power, wait 30 seconds, then turn standby to "on." When I turn the standby to the on position I get a loud pop. This happens at low and high volumes. I dont recall it always doing this but i could be wrong. is this normal or something to have checked out? Thanks

 

[mazzith]

My Mark IV does not make any sounds when I turn it off standby.

It sounds like it could be the standby switch arcing.

If you are brave enough you could pull the chassis out of the head and take a look at the back of the switch and see if there is any carbon build it. You can get some contact cleaner and spray the **** out of it while turning it on and off very quickly and repeatedly. Just make sure the amp is off and unplugged, which I think you know already. You can try to remove it that way, or just replace the switch all together.

That would be my guess, but I am not a certified amp engineer you know.

 

[Authorized Boogie]

This could also be related to a power tube - How old are the tubes in the amp? Do you have another pair you can swap out, one pair at a time?

 

[gibbycustom]

The tubes have about 60 hours on them. I'll try swapping them out.