What does the written number on El34's mean?

Discussion in 'The Workbench' started by ledvedder, Oct 22, 2021.

  1. ledvedder

    ledvedder Well-Known Member

    Joined:
    Jan 13, 2011
    Messages:
    588
    Likes Received:
    273
    Location:
    New Jersey
    I have a pair of Electro Harmonix el34's. They have 20 and 21 written on them. I also have a pair of JJ el34's that have 40 and 41 written on them, that came in my Origin 20. What do the numbers mean? Is it OK to put the EH tubes in it?
     
  2. thetragichero

    thetragichero Well-Known Member

    Joined:
    Jun 6, 2010
    Messages:
    3,346
    Likes Received:
    1,300
    Location:
    flo rida
    cathode biased el34s? yeah you should be fine
     
  3. william vogel

    william vogel Well-Known Member Gold Supporting Member

    Joined:
    Dec 18, 2016
    Messages:
    712
    Likes Received:
    826
    You’ll really need to be more specific like it’s numbered on a TubeDepot label or Apex Matching label fixed to the base of each tube or it’s printed on the glass, etc. My first guess is it’s a match rating because the numbers are close on each pair you describe but that’s the best I can do with the limited information.
     
  4. pedecamp

    pedecamp Well-Known Member

    Joined:
    Dec 7, 2009
    Messages:
    18,012
    Likes Received:
    18,159
    If you have a fixed bias amp and you buy replacement tubes and match the numbers to your old tubes you dont have to bias your amp. If you have a cathode bias amp those numbers dont mean anything. Pretty sure your Origin is cathode bias so you can ignore them.
     
  5. StingRay85

    StingRay85 Well-Known Member

    Joined:
    Aug 18, 2019
    Messages:
    1,784
    Likes Received:
    1,376
    Could be Maxi Matcher values for mA on 400V -36V bias

    But 20-21 would be on the very low side. 40 would be very strong tubes.
     
  6. thetragichero

    thetragichero Well-Known Member

    Joined:
    Jun 6, 2010
    Messages:
    3,346
    Likes Received:
    1,300
    Location:
    flo rida
    the numbers mean nothing (besides their proximity to each other in pairs/quads) without their test conditions being clearly stated. i would disregard the difference between each pair because it's meaningless without that data
     
    Pete Farrington and tschrama like this.

Share This Page