Wow Frankenstein tubes

[fenderdog]

Hey i just got the 50's RCA 6L6's for the vibrolux and the amp sounds great.
The thing is they arc like the lightning in those old Fankenstein movies.
From the top down, it splits like lightning but a soft arc and its a nice neon blue fork(it hugs the glass),and the funny thing is, both tubes do the same thing in almost the same spot.It's been on for a couple of hours and no change so it looks permanent.They have double foil o getters if that matters.
Just curious as to what would cause that,the JJ's get a bit blue but no B movie effect.

[Kap'n]

Arcing, like bright flashes, or just a soft blue glow?

Blue is fine, it's just a bit of gas in the tube - flashing is bad.

[fenderdog]

Its soft blue but very pronounced.They look like little upside down lava lamps only the pattern doesn't move around.
It's throughout both tubes and splits into forks.
I used it all night last night and there didn't seem to be a problem.
I'll try to take some close up pictures tonight when i get back from work and post them,it's really quite beautiful.

[refin]

Failed or out of spec component? Kap'n?

[boobtube21]

If it's not moving, and it's just a blue glow whatever the shape it's probably fine. But if it's "arcing" as you say, or moving around like constant lightning inside the tube that probably isn't good. Post those pics so we can see it when you get a chance.

[fenderdog]

I took some pics but my camera doesn't show the effect even on low light settings.Its an older one from 2004.

I shouldn't have said arcing.
It doesn't move around though,it seems to hug the glass and does look like gas.(soft blue)
The original Fender special tubes in it had a healthy blue hue to them and the JJ's would turn just a little blue but both had a solid hue throughout the tube.
These are not blue throughout but split up into branches like old B movie lightning effect(that's the only way i can think of describing it).
It doesn't move or flash though and both tubes have the same basic effect,almost identical,it starts at the top and then splits into a fork,then again and then kinda rolls around the bottom and up the back,although i can't see the back to well.
The plates look normal and the amp sounds great,very quiet.
I think its just an odd pattern that the gas is making,i just find it funny that both tubes do exactly the same thing pattern wise.

[Don]

Can you put the camera on a tripod and use a long shutter setting? That's how I took this pic-

[fenderdog]

Great pic,it looks exactly like that only it forks out instead of rings.
I can assume thats normal then?

[Don]

The tubes in my pic were completely normal and ran like that for years. They're Mesa branded 6L6 power tubes in a Mesa 5:50 Express.

[fenderdog]

Cool stuff,i wish my amp had a little opening in the front so i could see them when i play.

[boobtube21]

Pull the chassis out! Or turn your cab into a flip top

[fenderdog]

Pull the chassis out! Or turn your cab into a flip top

I'll see if i can find my jig-saw.