peeked in the back of my amp yesterday and noticed one of my rca 6v6's had a smallish spot of blue glow to it. is this something i should be concerned about? i know ive read about this b4, but cant remember what the verdict was...it still sounds fantastic, but i did notice a faint pop now and then, nothing obnoxious, pretty subtle really. but a faint pop nontheless. could these things be related?