Basic troubleshooting question: metallic hiss/hum

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Greg, Jun 27, 2005.

  1. Greg

    Greg Member

    Messages:
    163
    Joined:
    Jan 2, 2004
    Location:
    Oakland, CA
    I'm a newbie to tube amps.

    I have an amp that makes a faint metallic hiss/rattling sound when I hit certain notes (a low A, Bb, B). this lasts for just a couple of seconds. It is a faint noise, but enough to be noticeable and annoying. It does not do so with other notes.

    Before I take it to an amp tech, does this sound like an easy fix (tubes, maybe? which one(s)?)

    thanks in advance.
    Greg
     
  2. tonezoneonline

    tonezoneonline Member

    Messages:
    437
    Joined:
    Dec 15, 2003
    Location:
    central Illinois
    When asking for help trouble shooting an amp it never hurts to state what kind of amp your talking about.Imagine calling a mechanic and telling him'I have a car with a noise".
    I would first check the preamp tubes for your problem
     
  3. Greg

    Greg Member

    Messages:
    163
    Joined:
    Jan 2, 2004
    Location:
    Oakland, CA
    this is a '62 Brown Princeton.

    I don't think it's the preamp tubes ... I've switched them out and the problem remains. It's kind of a metallic rattle/shiver.
     
  4. Blue Strat

    Blue Strat Member

    Messages:
    30,023
    Joined:
    Aug 2, 2002
    Location:
    Sterling, VA (not far from Washington DC)
    Have you tried connecting the amp to an external speaker cab? This is the first thing I would try to eliminate mechanical buzzes or speaker problems.

    Power tubes are a contender as well as preamp tubes.
     
  5. unclej54

    unclej54 Guest

    if you've changed the preamp tubes then the first thing i'd look for is loose contacts in the preamp tube sockets. it's a fairly easy fix if you know how to drain your electrolitics..if you don't then get someone who does to do the repair..you could seriously hurt yourself with the amount of charge they store.
     

Share This Page