Loud Pop when switching from Standby

[TheRazMeister]

Hey guys,
All of a sudden my Rectoverb is making a loud POP when I switch from standby to the on position . At first I thought it was my delay unit but I removed everything except guitar to amp and the noise still exists. There are times it does it when I switch TO standby but it always makes the pop when I switch FROM standby (meaning ready to play). I'm thinking tubes because of an additional issue with a rattling noise on certain low notes when using the clean channel.
Anyone else experience this?

 

[MesaENGR412]

i experience the loud "pop" but no clean rattle. I'm not sure what it is...

-AJH

 

[tetsubin]

I'm thinking tubes because of an additional issue with a rattling noise on certain low notes when using the clean channel.
Anyone else experience this?

Yeah, I did. My old powertubes were giving me the finger everytime I turned standby off. Try some fresh ones.

 

[Chrissmoth]

Exactly the same

Replaced the power tubes & the pop was gone