Heater wiring question

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by JDJ, Jan 26, 2008.


  1. JDJ

    JDJ Supporting Member

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    '66 Pro Reverb. The green heater wires between the two power tube sockets are twisted an odd (as opposed to even) number of turns. Since that circuit runs on AC, does that matter? Don't really seem to get any hum from it.
     
  2. Structo

    Structo Member

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    It has more m0jo with uneven turns.....
     
  3. Rosewood

    Rosewood Member

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    Don't tell Eric Johnson or he'll be all over it.:cool:
     
  4. JDJ

    JDJ Supporting Member

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    You boys makin' fun of me?!
    :D
    Seriously, are they out of phase? Worth the trouble to fire up the iron to switch'm?
     
  5. SatelliteAmps

    SatelliteAmps Member

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    No, they aren't out of phase. The phasing has to do with where they are wired on the tube socket. The power tube heaters are on 2 & 7, so ideally you want the heater wire on pin 2 to go to pin 2 of the next power tube, and the one from pin 7 to go to pin 7 on the next tube.

    On some amps this is important, and some it isn't as important. Some tubes have more induced hum issues than others (12AX7 for instance) If you have no issues, then there is no problem with this.
     
  6. JDJ

    JDJ Supporting Member

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    Thanks. I have no hum and so no issues.
     

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