Date Codes On Telefunken 12AX7/ECC83

Discussion in 'Audio Hardware' started by NMyTree, Mar 29, 2008.

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  1. NMyTree

    NMyTree New Member Thread Starter

    Any tube gurus know how to read/interpret the date codes on Telefunken 12AX7/ECC83 Smooth Plates?

    I'm interested in WHitese's Telies, but I want to know what year they were manufactored. WHitese has some pics in his classified thread.

    http://www.stevehoffman.tv/forums/showthread.php?t=142304

    Or any suggestions on who could help me with this?

    Thanks.
     
  2. Steve Hoffman

    Steve Hoffman Your host Your Host

    No idea. If there is a diamond on the bottom (a true Tele) then I've never heard a difference in sound from one year to the next. I prefer ribbed. Better mids.
     
  3. crooner

    crooner Tube Marantzed

    I have been rolling different Telefunken 12AX7's in my Marantz 7 and I have sound sonic differences between them. I was trying to stash away the originals that came with the preamp (smooth plates circa 1964), and swapped them for other smooth plate <> Telefunkens I had in my tube box.

    The sound wasn't as good. Even though they do test great. Midrange was washed out and the overall resolution/detail suffered. They did give me more bass in the phono section, but at the expense of the mids.

    The originals are going back in...

    Getting the perfect set is trial and error I'm afraid...

    As for the date codes, there isn't a reliable code chart to decipher the manufacturing date. You can check for the plant (Ulm or Berlin), and that's basically it.

    I do know that ribbed plates are the oldest. I believe the smooth plates appeared in the mid 1960s. Perhaps the ones on my Marantz are some of the earliest. They do sound superb!
     
  4. Mike in OR

    Mike in OR Through Middle-earth...onto Heart of The Sunrise

    Location:
    Portland, Oregon
    You will not have etched date codes with Teles, as you do with Amperex and Mullard.
     
  5. MisterBritt

    MisterBritt Senior Member

    Location:
    Santa Fe, NM, USA
    I, too, have tried to find answers to the Telefunken date codes question. Maybe you've seen this: www.audiotubes.com/teledate.htm

    Unfortunately, I can't make heads nor tails of it. :shake:
     
  6. NMyTree

    NMyTree New Member Thread Starter

    Well, going by those codes (on Brent Jesse's website); the codes on WHitese's Telies seem to indicate they were all manufactored in 1962.

    Two of them have a "eg" designation and the other three have the "FI" designation.

    Which according to that code chart, both are ......1962 codes.

    Thanks guys!!!
     
  7. Barry Wom

    Barry Wom New Member

    Location:
    Pepperland

    seen his address??
    BRENT JESSEE RECORDING & SUPPLY, INC.
    1566 West Algonquin Road #111

    Hoffman Estates, IL 60192
     
  8. Analogman

    Analogman Well-Known Member



    Smooth plates came first
     
  9. crooner

    crooner Tube Marantzed

    Are you sure? My "green" Marantz 7C from 1959 was fitted with ribbed plate Tele's from the factory. Later units came with smooth plate tubes.
     
  10. Analogman

    Analogman Well-Known Member


    The 12AX7 has been "for sale" since 1947
    Why on Earth would you assume so much, merely from what came in your Marantz?
    Twelve years after the fact!
    Yes, I am "sure".
     
  11. Steve Hoffman

    Steve Hoffman Your host Your Host

    Aspen P. told me ribbed were first but really, I don't care!
     
  12. Abbagold

    Abbagold Working class hero

    Location:
    Natchitoches, LA
    I've rolled quite a few 12ax7's. I don't hear a difference between ribbed and smooth. I think it has more to do with the age of the tube and the factory run. Sometimes batches are better than others.
     
    wcarroll likes this.
  13. crooner

    crooner Tube Marantzed

    The 12Ax7, like many other early miniatures, was based on technology developed during the war and appeared as a consumer product in '47. However, Telefunken did not start production of their fabled ECC83 until the 1950's. I have a mid 1950's Telefunken "magnetofon" portable open reel deck and it came with ribbed plates ECC83's.
     
  14. Steve Hoffman

    Steve Hoffman Your host Your Host

    For her pleasure.
     
    jupiterboy likes this.
  15. Abbagold

    Abbagold Working class hero

    Location:
    Natchitoches, LA
    Dorky...but I always think the same thing.
     
  16. Steve Hoffman

    Steve Hoffman Your host Your Host

    Many tube loving audiophiles have no sense of humor whatsoever but I keep trying..
     
    kevinsinnott likes this.
  17. Done A Ton

    Done A Ton Birdbrain

    Location:
    Rural Kansas
    You stole my line.
     
  18. Analogman

    Analogman Well-Known Member


    So?
    I cannot "prove" this (and I am not going to try to), but it is my understanding after much reading and owning many of these 12Ax7s that the smooth plates were all manufactured in Berlin and the ribbed plates in the Ulm factory. It DOES NOT prove anything, but I have never owned a smooth plate from Ulm or a ribbed plate from Berlin. I would suspect that in the years immediately following the War, production in Ulm was more "up to speed" for obvious reasons. This may account for more ribbed plate sightings in early equipment. Berlin was plagued with all sorts of shortages for sometime after the end of WWII and all the other issues surrounding the occupation (logistical).
    Anecdotal observations of what tube came installed in what (minimal samples) piece of equipment doesn't change the fact that the smooth plate came first.
    Only date codes and actual samples and Telefunken's production records can do this. And all of that OBJECTIVE data would SEEM to indicate the smooth plate came first.
    About 100 other folks that know a great deal more than I seem to agree (based ONLY on what I have read).
    Just let your fingers do the walking; "Google" it. Read the statements from the many long time dealers, people who reside in Germany and other long time collectors.
    They are both fine tubes. I really don't see what the matter is anyway; which "came first".
    I only commented as you had made a statement as "fact" with nothing more than anecdotal, circumstantial evidence to back it up.
    Bad form in my opinion.
    Enjoy your tubes!
     
  19. VilMortem

    VilMortem New Member


    I have a ribbed plate ECC83 from Berlin , code "B5100901" (Berlin, 15-Sept-1960) tele1.JPG tele2.JPG tele3.JPG
     
  20. Steve Hoffman

    Steve Hoffman Your host Your Host

  21. VilMortem

    VilMortem New Member

  22. Steve Hoffman

    Steve Hoffman Your host Your Host

    I didn't think they had a plant there after the war. I thought only ULM. Is that why some of my mini-pin 12AU7 and 12AX7 Teles say "Made In Germany" and some others say "Made In Western Germany"?
     
  23. indy mike

    indy mike Forum Pest

    West Germany on goods started showing up during the Cold War era (around 1949 to when the Berlin Wall came down); seems like Western Zone also identified goods from the non-Communist sector of Germany.
     
  24. Steve Hoffman

    Steve Hoffman Your host Your Host

    Wouldn't have anything to do with my question, which was: Why do some 1960's Telefunken tubes say "MADE IN GERMANY" and some others say "MADE IN WEST GERMANY"? Was that a plant thing?
     
  25. Paul K

    Paul K Senior Member

    Location:
    Toronto, Canada
    I have a question. Sometime I must have purchased a Tele smooth plate 12 AX7 and it finally dawned on me that this thing might be fake. It has the diamond on the bottom, BUT the painting is immaculate. It won't rub off no matter what you do.
    It looks similar to the real Telefunken and rebranded Fisher ones I have (this one has Telefunken written on it) but I really can't tell...is there something that will give it away besides those factors?
     
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