whats wrong with my tubes

[cremulator]

Ive read in one of my amp books that if your tubes begin to glow blue that its the beginning of the end.. well my stock tubes in my 5150 are glowing pretty damn blue [img]graemlins/scratchhead.gif[/img] and I dont know what to do...is this normal...I just got the damn thing four days ago..what should I do ?

and if I need new tubes which brand should I get. It dosent matter on price..

[redmanjj]

Re: whats wrong with my tubes

I am indeed not an expert, but I believe the level of bias can affect the colour of your tubes while in use. Get it checked either way. If you're buying new power tubes, you haev to rebias anyway.

[Cleveland Metal]

Re: whats wrong with my tubes

Many tubes will glow a nice dark blue...It's from impurities, like cobalt, flourescing when electrons from the cathode hit parts in the tube. Svetlana tubes usually do it for one. It's just part of the way they operate inside.

However, ionized air that has leaked into the tube is a strong purple, almost pink. That means the tube is on it's way out and it's time to replace it, like now...

I used Teslas and Svetlanas in my 5150s for some time. I like the Svetlana tube the best.

[krimson]

Re: whats wrong with my tubes

Damn. I have an old Ampeg V2 head and those suckers glow blue like crazy. I guess its time to change out the original tubes.