Mismatched Power Tubes

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by vibrasonic, Feb 20, 2012.

  1. vibrasonic

    vibrasonic Member

    Messages:
    1,878
    Joined:
    Dec 16, 2011
    How far off can power tubes be off or mismatched before it creates problems
    for your amp. Is 8 to 10 milliamps too far off?
     
  2. Blue Strat

    Blue Strat Member

    Messages:
    30,036
    Joined:
    Aug 2, 2002
    Location:
    Sterling, VA (not far from Washington DC)
    8-10mA isn't that bad. It's probably worse for 6V6s or EL84s than for 6L6s or EL34s because of the difference in bias levels (around 20mA for 6V6s/EL84s, 35mA for 6L6s/EL34s) but it's not dangerous for anything.
     
  3. vibrasonic

    vibrasonic Member

    Messages:
    1,878
    Joined:
    Dec 16, 2011
    Thanks Mike
    I just got a set of GE 5881's that are 8mA off, that i am now going to try in my 6G9A
    Tremolux.
     
  4. Blue Strat

    Blue Strat Member

    Messages:
    30,036
    Joined:
    Aug 2, 2002
    Location:
    Sterling, VA (not far from Washington DC)
    Shouldn't be a problem.
     
  5. Rambergwest

    Rambergwest Member

    Messages:
    914
    Joined:
    May 26, 2011
    Try both tubes in both sockets you might find that one particular orientation sounds noticeably better.
     
  6. guitarcapo

    guitarcapo Senior Member

    Messages:
    2,337
    Joined:
    Mar 16, 2010
    Some people offset them a little on purpose.
     

Share This Page