1/4 amps hum at home, but that amp isn't humming in studio...

Discussion in 'Amp Tech Center' started by nedorama, Apr 30, 2021.

  1. nedorama

    nedorama Tele-Meister

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    I have 4 amps, all on the same outlet:
    - 65 Fender Tremolux
    - 74 Fender Princeton
    - 80 Fender Princeton Reverb
    - Dr. Z MAZ 18 Jr.

    The Tremolux, Princeton and the Dr. Z are dead quiet when turned on and plugged into.
    The Princeton Reverb has hum with nothing plugged into the input, and hum goes up with volume. Hum increases as reverb is turned up.

    I took the Princeton Reverb to rehearsal yesterday, and it was dead quiet...

    This is an issue that's tough, as if I take it to my amp tech, it will be quiet as well...

    I've even tried plugging the Princeton Reverb in to a Hum-X isolation transformer with no change...

    Any thoughts? Thanks!
     
  2. Wallaby

    Wallaby Friend of Leo's

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    I guess I'd try another outlet in another room and see what happens?
     
  3. Fluddman

    Fluddman Tele-Holic

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    If it happens at home but not at the studio I would suggest getting the wiring checked at your home.

    Cheers
     
  4. wabashslim

    wabashslim Friend of Leo's

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    If the amps are close together maybe it's picking up noise from another amp's tranny or wiring?

    Do what Wallaby said...
     
  5. Bob Arbogast

    Bob Arbogast Tele-Afflicted Silver Supporter

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    Sounds like the input jack is not shorting.
     
    sudogeek likes this.
  6. nedorama

    nedorama Tele-Meister

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    The outlet isn't the problem - as I stated in my post, all 4 amps are plugged into the same outlet and the other 3 are dead quiet. Doesn't matter if the amps are next to each other or separated.

    Shorting jack may be it, will check.
     
  7. schmee

    schmee Doctor of Teleocity Ad Free Member

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    You can check that the AC wiring is correct if it's an old amp that was rewired to 3 prong. The Black and White connections DO matter.
    I like the "Input Jack not shorting" idea too. The contact points can be cleaned.

    But being a reverb amp, it may just be that. They can be noisier. Does it quiet down like the others with the reverb turned all the way down? With the tank cables unplugged?
    Reverb tube?
    Dirty reverb cable jacks?

    The HumX are worthless devices.
     
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