cracking sound when I turn my amp on

Discussion in 'Amps and Cabs' started by pickslide, Mar 28, 2015.

  1. pickslide

    pickslide Member

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    When I turn my vintage Marshall head on I get a staticy/crackling sound that comes on a bit strong and then fades out once the amp has been on for about 1-2 min. Then it is totally gone. Any idea what that could be?
     
  2. DaveKS

    DaveKS Member

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    Dirty tube sockets/pins or a power tube that's probably not long for this world would be my guesses.
     
  3. pickslide

    pickslide Member

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    I was thinking maybe something like this. Just hoping for nothing serious
     
  4. jbraun002

    jbraun002 Member

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    On a bandmaster I have I've encountered this, and it was due to a connection needing a touch up solder. YMMV, and of course it might just need some the tube socket cleaned or a new tube.
     
  5. Blue Strat

    Blue Strat Member

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    A lot of new production preamp tubes do this. No biggie.
     
  6. jbert58

    jbert58 Member

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    I had a similar problem with a Genz Benz Black Pearl amp recently and it was the power tubes (EL84) - 3 out of 4 were failing. A new matched quartet of tubes and the amp is as quiet as new.

    jbert
     
  7. Rick57

    Rick57 Member

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    That's not serious at all. Is it happening before you plug in? I ask because it could be a number of things. A loose cord end. It could be one of you knobs on guitar is loose. Or the input jack needs to be tightened. I would check connections first then tubes
     
  8. ELmiguel

    ELmiguel Member

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    My amp did this. It was preamp tubes. Easy and not too expensive fix. Don't need a tech because you don't need to rebias it.
    First I would try just taking them out one at a time and pushing them in and out of the socket a few times. It might just be corrosion.
     
  9. zenas

    zenas Member

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    My 1974 1987 Marshall did that for years then got to the point I needed to fix it. Ended up being one of the 100K plate load resisters on V1.

    Some change all of those on old amps, I change them when they're bad. I think that's the only one I've ever changed.
     
  10. ken374

    ken374 Member

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    Spray the tubes pins with Deoxit 5 and work it in a good few times, worked great for me.
     
  11. Vai81

    Vai81 Member

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    Leaking resister/capacitor before the FX loop or PI.
     
  12. pickslide

    pickslide Member

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