I just bought a randall rg-50tc tube amp.. and everytime I switch from the clean channel to the gain channel, I hear a large "pop" in the amp itself... is this normal?

also, I want to buy a footswitch for it, which one should I get if just wanted to switch channels and maybe have some effects with it
is it all tube or a single tube?
if its all tube idk, you might wanna call up a tech. guy.
if its a single tube, then it probably is.
my half stack has a single tube and it makes a nice pop sound when i flick it on, because
it doesn't req. a standby.
i'm guessing it's an all-tube amp since there's like.. 6 tubes and it says on the randall website :
# Two EL34 power tubes
# Four 12AX7EH’s

and it's weird... I jammed with some friends and when I cranked the volume knob up, I started hearing a weird sound.. like they're was a fan running in the amp.. at lower volumes it didn't happen
mine does this too.

but I dont use the gain channel anways.
(it does this for the clean boost too though)

and for the footswitch, it requires a 6 pin, 4 button footswitch
so you cant just get any old one

unless youre reffering to an effect pedal....because amp footswitched dont have effect in them
You may have a bad capacitor or the solder to the capacitor is defective (cold-solder.)
should I bring it to a guitar shop to see if they can repair it? because it sounds fine at lower volumes (except for the popping part)