Jolida & Johnny Guitar brand tubes - Ever hear of these?

[Mars Amp Repair]

More weird branded tubes in this old JCM800 2210 Marshall.
Again, from back in the day when many different companies self-branded tubes.

[mozz]

If that's a 12ax7, definitely not a American made tube. Pointed pin ends?

[Helmholtz]

They look like chinese (Shuguang) ECC83s.

[The Dude]

Looks like Johnny and Jolida have lost their vacuum.

[Helmholtz]

Looks like Johnny and Jolida have lost their vacuum.

Why?
The getter deposit looks fine.

[The Dude]

I was referring to how the tube glass has started to become white at the tube bases, though could be something else.

[Helmholtz]

If oxygen/air had entered to tube, the getter metal layer on top would turn white or disappear.

[g1]

If oxygen/air had entered to tube, the getter metal layer on top would turn white or disappear.

This I had never noticed. Just happened to have a bad 12AX7 (also Chinese) on my desk, so I broke it. The getter splash disappeared in about a minute.
Could a tube that was not sealed up quick enough during assembly do what the picture shows? I don't get it.

[Justin Thomas]

Didn't Stan say years ago that anyone could get anything printed on their tubes if you ordered from China in lots of like 1,000? Maybe these are some of those... I always thought I'd like to do that, if I ever win enough money to buy a lot of 1,000 tubes...

Sumo Enzo ski jumping would be cool too...

Jusrin

[Tom Phillips]

This I had never noticed. Just happened to have a bad 12AX7 (also Chinese) on my desk, so I broke it. The getter splash disappeared in about a minute.
Could a tube that was not sealed up quick enough during assembly do what the picture shows? I don't get it.

That bad looking stuff at the bottom of the tube is a mystery to me. Maybe it is contamination of some sort but it looks like the getter flashing at the top of the tube is still good. During the manufacturing process, the getter is "flashed" after the tube is evacuated and sealed. This is done by heating the getter holder via an induction heating process.

[g1]

That bad looking stuff at the bottom of the tube is a mystery to me.

Probably just coincidence, but the whitish part is the same area that would sit in the shield base of a socket.

[The Dude]

Spit balling here, but wouldn't the location of getter material depend on tube orientation? I guess I've never paid that much attention to the phenomena. In other words, if the tube hung down like in a Fender amp, the material would be opposite the tube pins. If the tube stood up, like in a Marshall amp the material would fall towards the tube base. I'm really not sure. As I said, I've never paid that much attention to it. It seems logical that gravity would have an effect.

[Helmholtz]

During the getter flashing process (after the tube is pumped and sealed) the getter metal is evaporated by RF induction heating from the getter pans and then condenses on the coolest part of the inner surface of the envelope as a mirror.
With preamp tubes this is typically at the top of the tube (as the getter is a conductor you don't want it to be close to the pins).
The getter mirror does not migrate with use.

https://en.wikipedia.org/wiki/Getter

[The Dude]

Agreed, but I've seen it flake off in tiny bits when vacuum is lost. Is it not possible that it could fall to the tube base?

Edit: If you look closely at those tubes, you can even see what looks to be streaks of getter material running down the sides of the tubes, though it could just be reflections or something in the photo.

[Helmholtz]

I assume the flakes you saw were mica particles.