well, i don't have a pic, but tonight i pulled the power tubes out of my friends amp, and the top of one of them looked as if it had melted a bit, and was a milky white color.

any ideas?

i don't have much experience either, but it sounds to me like it may have overheated or possibly gotten moisture on it while it was hot. i've seen car headlight bulbs do what i think you're talking about. they just get wicked hot and part of the glass tube gives way.

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Originally posted by jonc:
well, i don't have a pic, but tonight i pulled the power tubes out of my friends amp, and the top of one of them looked as if it had melted a bit, and was a milky white color.

any ideas?

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To the best of my knowledge, the milky white color usually occurs when you play a cover of a song by the band Cream.




Harris

White means air has gotten inside the tube and started to oxidise the silver stuff on the glass.

as he said above a vacuum leak

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Originally posted by Harris:

quote:

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Originally posted by jonc:
well, i don't have a pic, but tonight i pulled the power tubes out of my friends amp, and the top of one of them looked as if it had melted a bit, and was a milky white color.

any ideas?

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To the best of my knowledge, the milky white color usually occurs when you play a cover of a song by the band Cream.




Harris

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Yeah I think I know the song..."In the white tube with black ......"

Sorry I had too..!!

Chow,
Seegs

Frosting on the top of a bottle means it has lost it's vacuum. If you look around the base, you may find a hairline crack near one of the pins that is the cause of the vacuum loss. Needless to say, the tube is ruined.

thanks td, et al. yup, cracked. and, going back to the guy it was bought from, who said "amp in great shape, works perfect, recently looked at by my amp tech..."

right!

LOL! That means it was in his garage inhabitated by a family of large squirrels until the auction was over.

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Originally posted by Morgan:
LOL! That means it was in his garage inhabitated by a family of large squirrels until the auction was over.

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