Mystery EL34

[odourboy]

I need some help from the forum. A power tube failed recently in one of my 50W Bluesmaster amps. This was a particularly sweet sounding head - which in this case, I attributed to the power tubes. Problem is, when I pulled the tubes to replace them, I realized I did not know where they came from or who made them - all the markings had rubbed off.

So, here is a high resolution pic of the failed tube from a few angles. Does anyone recognize this fellow?

Thanks in advance!
Brian

[brentm]

I love a good mystery. I'm not all that familiar with EL34 guts, but just referencing other tubes. They look like mullards!

https://www.kcanostubes.com/content/nos ... rs-singles

[Cantplay]

Mullards will have a hole in the alignment pin.

John

[Cliff Schecht]

And any real Mullards will have clear etching in the glass near the base indicating place of manufacture and lot #.

[Structo]

Brian, are these current production EL34's?

Black base, no windows on weld seam.

Two mall rectangular openings in plate.

Round getter?

[Structo]

Kind of looke like these JJ's.

Except the spot welds on the plate seams aren't quite the same.

The Chinese EL34's tend to have brown bases.

[img:364:500]https://www.guitarsunited.com/images/136430-1-big.jpg[/img]

[ChrisM]

Kind of looke like these JJ's.

Except the spot welds on the plate seams aren't quite the same.

The Chinese EL34's tend to have brown bases.

[img:364:500]https://www.guitarsunited.com/images/136430-1-big.jpg[/img]

Compare the getters of the two, very different.

[odourboy]

Brian, are these current production EL34's?

Black base, no windows on weld seam.

Two mall rectangular openings in plate.

Round getter?

I don't know.

They came out of a 'new' Ruby box but I think I must have stashed something else in the boxes at some point because they don't look like current production Ruby EL34s.

[odourboy]

I should add, I'm not in the habit of buying expensive power tubes. I'm thinking these were probably pulled from an old amp and after testing okay, got put on the self in some recycled boxes.

[odourboy]

Mullards will have a hole in the alignment pin.

John

The guts do look somewhat like the Xf1 Mullards. There is no hole in the guide pin (fairly telling that it's not a Mullard, but not conclusive). BTW, not that evident in the photo i posted but the base is brown.

I hope they're not Mullards because I could not afford to replace them!

[67plexi]

Looks like Matsushita made in Japan 60's 70's,

The Matsushita plant was set up by Philips, Can be identified by

a single seam at the top of the tube. No hole in center pin.

[odourboy]

Found them!

EL34 TESLA NOS 1984 Brown Base Welded Plates Dual Round "O" Halo Getter Zavod Trinec Factory Code 37

These match mine perfectly. $200+ per pair

(Now, I wonder where I got them?)

[Structo]

Nice!

[M Fowler]

Now keep track of that info

Mark