tube ID....

[bluesy]

.....Just found a tube in a small stash of 12A*7's. The only thing I can read on it is: B6A3 etched on the side. Above that looks like: 163 or I63. The only other thing is what appears to be a BACKWARDS "J" centered on the bottom between the 9 pins. Round halo thing on top. Plates are "laddered". so to speak. Any educated guesses? Maybe it's useful.

 

[rockon1]

3rd week in January1966 Mullard short plate. I63 is the design level. B stands for Blackburn England 6 stands for 1966 A is January and 3 is the 3rd week.Bob

 

[bluesy]

....is there any way to tell whether it's an AX, AY, or AU? Can it be used as a pre amp tube? Sounds like it might be a lot of fun if usable.

 

[rockon1]

3rd week in January 1966 Mullard short plate 12AX7. The guts should look like these. That code should be near the bottom like on these. Bob

 

[bluesy]

....Now I feel fairly confident trying it out! V1, 2, or 3 in a Bassman ltd?

 

[bluesy]

....it looks exactly like your pics. Thank you so much for that.

 

[rockon1]

There ya go. A hidden gem! Bob