Blueish Glow in 2A3

[Jameson]

I have an ElectroHarmonix Gold 2A3 running in the Stereomour II. I noticed last night that there's a slight blue glow around the top on one tube. Is that tube going bad?

 

[Paul Birkeland]

That's normal and a sign of a strong vacuum.

 

[Natural Sound]

I have some Sovtek 2A3's that have a blue glow. In my case it isn't an issue. Here is some more information.

https://blog.thetubestore.com/understanding-blue-glow-in-your-amp-tubes/

 

[Jameson]

Hell yeah, strong vacuum.

Thanks guys.