Telefunken 12AX7....without diamond

Curt

Member
Messages
6,974
I just picked up a new unopened Telefunken 12AX7 from an old box of tubes in our metrology dept.
The lettering is perfect. The question is that it doesn't have the diamond on the bottom of the tube like my other telefunken's have. It say's "Made in Western Germany" and has a QA Q1 on the side.

Any idea why no diamond?
 

Blue Strat

Member
Messages
30,194
Originally posted by Curt


Any idea why no diamond?
Yes, it likely wasn't manufactured by Telefunken. Only an inspection of the internals by a trained eye will yield an answer to this. Photos?
 

Curt

Member
Messages
6,974
Funny you should ask. A while back, I walked into our Metrology dept. and opened three drawers that looked like they hadn't been opened in ten years. It was like finding buried treasure. I asked the manager what he was going to do with all these "worthless old tubes". He said "he didn't really care what happend to them".
He asked me if I wanted them. I said "yea, sure, I guess so."
Brand new, never opened 12AX7, 5751's, Telefunkens, RCA's Mullards, Amperex, Siemens, GE's etc. Not to mention all the new EL84, and 34's and a lot more very valuable power tubes.
A fellow 23 year old engineers saw me walk in to my office with the large box of tubes. He asked me "what are you going to with all that crap in the box?" I just smiled.
Anyway..I saved a few tubes.. The rest are gone.
 

drbob1

Gold Supporting Member
Messages
28,577
My sob story, the local tube guy got ill. I told him if he decided to close up shop, call me and I'd give him a fair price for his tubes. Couple of months later, stopped by again: oh yeah, some guys from the city had been by and bought all the useful tubes but I was welcome to the radio stuff that was left...:mad:

Oh well. Congrats on your score!
 

TheAmpNerd

Member
Messages
1,056
Originally posted by Blue Strat
Yes, it likely wasn't manufactured by Telefunken. Only an inspection of the internals by a trained eye will yield an answer to this. Photos?
Mike,

I've come across some of the smooth plate telefunkens
without the diamond on the bottom. The innards are
identical to the other telefunkens that I have that are
the same tube. : )
 

Blue Strat

Member
Messages
30,194
Originally posted by Igneous
Ive seen mullard innards in a 'labeled' tele before
Yep, I've seen them too. Also RFTs in Tele "clothing".

The one mentioned above is actually a Tele without the diamond. The getter is the giveaway.
 




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