Hey im having some trouble with my bassman 70. One of my output tubes (6L6) isnt glowing blue when i turn my stand by switch off to play. The tube is glowing like the other just doesnt have the blue glow. They are new tubes with about an hour of playtime.What could be the cause of this?
Tubes can glow orange, yellow, red, or blue. Unless you start noticing sudden drops in volume, you'll be fine.
There's no rule that says they have to glow blue in order to work. Some just do.
I believe a strong blue glow means that there isn't a complete vacuum in the tube. If it's just a little; nothing to worry about.