Is this a microphonic tube?

Discussion in 'Amps and Cabs' started by Paul Anderberg, Jan 17, 2015.

  1. Paul Anderberg

    Paul Anderberg Member

    Messages:
    1,145
    Joined:
    Aug 5, 2010
    Location:
    San Diego, CA
    So, I switched out some tubes in my Morgan a little bit ago (EF86 and EL84) and now there's a high pitch ringing whenever i hit a G note. It's mostly on the low G, but when it's an octave up, it's fainter but still there.

    Is this the tube being microphonic or something else?
     
  2. Blue Strat

    Blue Strat Member

    Messages:
    30,029
    Joined:
    Aug 2, 2002
    Location:
    Sterling, VA (not far from Washington DC)
    Does either tube ring when you tap on it lightly (with the amp on)? That's the test.

    Note that a dull thud or other minimal sound isn't unusual.

    Also, put the old tubes back in and see if they do it. If not, install one new tube at a time and check.
     
  3. sadowsky13

    sadowsky13 Member

    Messages:
    65
    Joined:
    Feb 25, 2007
    Im no pro but I have an ef86 in my 65 amps soho. It's a very finicky tube, As mentioned throw the old one back in and see how it sounds. I am thinking yes it will be thd ef86
     
  4. vicdeluca71

    vicdeluca71 Member

    Messages:
    955
    Joined:
    Nov 16, 2008
    Location:
    PA-coal country

Share This Page