Ye Olde Static Noise Thread

Discussion in 'Amp Tech Center' started by Luthier Vandros, Aug 22, 2019.

  1. Luthier Vandros

    Luthier Vandros Tele-Holic Silver Supporter

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    Amp: 65 PRRI with new tubes and reverb cable.

    Symptoms: random static noise exacerbated by tapping anywhere on the amp - even with PI pulled. No flashing on any tubes accompanying the noise.

    Possible clue: added 1M resistor to PI Grid the day before. This is my first time playing it since.

    Not in the mood for this! The solder job on the 1M grid stopper is clean, as I'm a builder with experience. Just no mental capacity left due to new dad sleep deprivation.

    Halp!
     
    Last edited: Aug 22, 2019
  2. peteb

    peteb Friend of Leo's

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    The static is not signal related.

    Only the signal, not the power supply to the tubes, goes thru a grid stopper resistor.




    The grid stopper is not the problem.
     
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  3. Luthier Vandros

    Luthier Vandros Tele-Holic Silver Supporter

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    Thanks, PeteB. Gonna pull the chassis and ride her to chopstick city.
     
  4. Luthier Vandros

    Luthier Vandros Tele-Holic Silver Supporter

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    v5 or its socket is the culprit. The noise appears when I gently tap or rock the tube. It's a relief to know the socket is chassis mounted, so I'm not worried about anything else.

    Edit: moving the suspected tube into the next socket seems to have stopped the noise. Strange. Will have a look at the socket tomorrow.
     
    Last edited: Aug 22, 2019
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  5. Luthier Vandros

    Luthier Vandros Tele-Holic Silver Supporter

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    A couple of loose pins were causing the problem. Again, really pleased with the construction of the Fender RI. Ceramic octal sockets, belton bear traps, etc. I was also able to reduce a bit of hum in the verb circuit by moving some wires around.

    A word of caution about TAD 9-pin tubes. The pins are fragile as pot metal spaghetti. I broke one off after carefully removing and reinstalling it twice. Great sound, however.
     
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