#1
The top of one of my power tubes (EL84) is white, whereas the other three power tubes, and the three preamp tubes are all kind of metallic at the top. Is that bad?
#2
Definite Uranium exposure. I'd call NORAD.


As long as it works alright, you should be fine. If something were wrong, you'd know.
I'm putting my GAS on hold
for a couple months in order to pimp my ride.


Don't judge me.
#3
oh ****, I'll get on the phone!

haha, okay. I figured if it sounded okay it would be okay, but I just don't know with these things... tube amps are a bit volatile.
#4
Quote by wiredisme
The top of one of my power tubes (EL84) is white, whereas the other three power tubes, and the three preamp tubes are all kind of metallic at the top. Is that bad?


Very bad, stop using it now (in all seriousness). Means that there's a gas leak. Vacuum tubes are called *vacuum* because they need vacuum inside to run. The silvery/metallic coating is the "getter" that absorbs extra gas in the tube, making the vacuum last longer. If it's white, a leak developed, the getter is used up, and the tube is now junk ('cause it's now a tube, not a vacuum tube).

Needs to be replaced. Since it's an output tube, they all need to be replaced.

Sorry.


Edited for clarity...
Quote by kcdakrt
DLrocket89 makes my ug experience better!


Member of the official GB&C "Who to Listen to" list

Kit Amp Building Tutorial
Last edited by DLrocket89 at Feb 26, 2009,
#5
looks like something is wrong after all. that tube isn't lit up while i'm playing. so i'm guessing it's dead. I just had the tubes replaced by a shop a few days ago, so what's up? Did they screw something up or did I just get a bad tube?
#6
Quote by wiredisme
looks like something is wrong after all. that tube isn't lit up while i'm playing. so i'm guessing it's dead. I just had the tubes replaced by a shop a few days ago, so what's up? Did they screw something up or did I just get a bad tube?


Could've been either. I just replaced tubes in a customer's DSL50 head and one of the 12AX7s was bad, from the factory. Getter was good (unlike you case here), but it didn't work. That said, if they screw with it when inserting it, yeah, it can be damaged to create a gas leak.
Quote by kcdakrt
DLrocket89 makes my ug experience better!


Member of the official GB&C "Who to Listen to" list

Kit Amp Building Tutorial