Re: tube flare-up

["david j. brown" <nonidesign@xxxxxxxxxxxxxxxx>]

I have a 5AR4 in the rectifier stage of my Sonny Jr 2 amp. When I turn the
amp on I have the stand by switch in the on position. I've noticed that blue
sparks, or sometimes a small blue flame, will appear when I switch the stand
by off. I also noticed that when I wait until the amp has warmed up for a
while before I switch the stand by off that neither of these things happen.
Neither the fins on this tube, nor any of the other tubes in the amp, ever
glow red. The amp works fine despite the activity in the rectifier tube.

I removed the tube and replaced it with an identical tube and the problem
has stopped but I am curious if the sparks/flames:
1. indicate a dying tube (it tests fine)
2. This isn't really a problem and just waiting a longer time for the amp to
warm up will prevent the problem and allow me to use the sparking/flaming
tube. 

Any amp doctors out there have any info?

Big thanks
D