2. tech-talk
  3. 180910-178395

ACME 300B matched pair - different blue glow intensity - new in amp world

Hi, I bought new pair matched ACME 300B. 

Everything is perfect, but between tubes there is small difference in blue glow intensity (photo in attachment). Amp socket swap, doesn't change that. One is brighter that second one.

I know the basics (from where is this effect and why), but I don't have a practice..

Due tubes where quite expensive, I just wanna be sure that everything its fine, or this difference in blue glow intensity, mean something that I should worry about ?

Thanks for help

https://postimg.cc/gallery/dT5SNg0

wiaderko

Showing 2 responses by ghdprentice

ghdprentice
7,646 posts
 

Excellent video!

ghdprentice
7,646 posts
 

So, I believe what the photos show is that one tube has the blue glow and one doesn’t and the tube that glows switches sockets… showing it is a characteristic of the tube and not the amp.

 

Yes, I would be concerned. Whenever, I have detected a difference in the look of a tube it has indicated something wrong. While it has not happened often. 
 

I would contact the dealer you bought them from. There has to be a difference in vacuum or the components inside or something. I do not consider myself a tube “expert”, although I run 40+ tubes and have used them in one or more components for well over 20 years.

More to discover