Identify this NOS 12AX7/ECC83??

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by bryan k, Feb 19, 2012.

  1. bryan k

    bryan k Member

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    Well, its not NOS,....but its USED old stock.....I cant figure it out, ive never seen a type like this before.

    It clearly says on it "made in Holland", but i dont see any date codes. Yet there is a date (in green lettering) that says "FEb 1954" (starting to fade/wipe off), but its not any sort of encrypted code. Also notice the weird looking Getter....its a solid oval plate.

    I cant find any sort of "manufacturing plat code/symbol" anywhere on this thing....

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  2. Blue Strat

    Blue Strat Member

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    How about a clear shot, dead on the surface of one of the plates?
     
  3. antbosca

    antbosca Member

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    Hmmm. Yes, the getter is weird. I've no idea, sorry to say, but I was wondering? How does it sound?
     
  4. bryan k

    bryan k Member

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    I'm not at home with the tube right now..... But when I get home tonight, I'll post a shot of the plates
     
  5. jamesie

    jamesie Member

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    made in holland ? i think phillips
     
  6. john l

    john l Member

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    Not to hijack the thread but maybe after you sort this guy out you can help me identify my little mystery tube as well Mike. Says USA 7025 and I believe it says UG under that. I really like this thing in a few of my amps and would be interested in buying more.
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  7. bryan k

    bryan k Member

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    Thats a RCA
     
  8. bryan k

    bryan k Member

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    Heres 2 more images of my mystery tube plates....notice how one of the pates has a numeric "73" clamped to one of them....

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  9. Timbre Wolf

    Timbre Wolf GoldMember Supporter Gold Supporting Member

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    The OP's mystery tube is an early Tungsram. See the numbered metal tag inside? That's unique to Tungsram.

    Yes - that other photo was of an RCA. The key characteristic is the flattened-side mica disks.
     
  10. davestp1

    davestp1 Supporting Member

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  11. Blue Strat

    Blue Strat Member

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    GE as indicated by the "stencil" font and dots for the 6L6GC marking etched into the glass.
     
    Last edited: Feb 20, 2012
  12. davestp1

    davestp1 Supporting Member

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    Thanks Blue Strat....
     
  13. john l

    john l Member

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    Cool thanks, I know that RCA had more than one kind of 12AX7. which one is this?

    EDIT
    LOL This was probably back in the day where the terms 7025 and 12AX7 were not used interchaneably. What your saying is that this is an RCA 7025 right?
     
  14. wahwah

    wahwah Member

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    For it to be an RCA, the '7025' would have to be inside a hexagon. I don't see that on this tube. That looks more like a GE to me.



    Cheers.................................. wahwah
     
  15. Timbre Wolf

    Timbre Wolf GoldMember Supporter Gold Supporting Member

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    That is a GE 6L6GC, as Blue Strat has already identified. Don't generalize about the flattened-edge micas, as that i.d. trick only applies to the 12AX7 in question.

    That tube is a GE. But for others reading this - not all tubes with dots are GE... Westinghouse also used a slightly different kind of dot pattern.

    - Thom
     
  16. bryan k

    bryan k Member

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    thanks for identifying the Tungsram!

    Its a pretty decent tube. I found it to be very well balanced with a very slight bit of upper mid push. Possibly a bit brighter than most 12ax7s ive tried. But a very well balanced sound indeed.

    I pulled this out of my tube stash the other day (from my old "tube rolling dayz") and always wondered what it was.....
     
  17. Timbre Wolf

    Timbre Wolf GoldMember Supporter Gold Supporting Member

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    I like those old Tungsram, too, and find them to be very good. Glad yours works well.

    - T
     
    Last edited: Feb 20, 2012
  18. Buddy Boy

    Buddy Boy Member

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    Tungsrams are great tubes! The best Boogie I owned was full of them.
     

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