Microphonic tube ?

Discussion in 'Glowing Bottle Tube Amp Forum' started by SnidelyWhiplash, May 17, 2021.

  1. SnidelyWhiplash

    SnidelyWhiplash Friend of Leo's

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    I have a microphonic RCA 12ax7 in V1 of my Princeton clone. I know, already replaced. My ? is, could I use it in another position if it tests well or should I dispose of it as a matter of course??? :cool:
     
  2. Dacious

    Dacious Poster Extraordinaire

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    Try it in phase inverter slot.
     
  3. telemnemonics

    telemnemonics Telefied Ad Free Member

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    I always put a good sounding but microphonic preamp tube in the next slot, which is usually tone control recovery, and see if it works there.
    Phase inverter I try last.
     
  4. kbold

    kbold Friend of Leo's

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    No harm trying it in other positions. V1 is where you get the highest gain, so it would perform worst there.
     
  5. Andy ZZ

    Andy ZZ Tele-Meister

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    PI and Vibrato Ocsillator if you have an amp with Vib.
     
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  6. Abu Twangy

    Abu Twangy Friend of Leo's

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    I shudder to think of all the otherwise fine 12AX7s I tossed because they became microphonic in V1. Nowadays a tube has to totally fail or redplate for me to toss it.
     
  7. Les Paul lover

    Les Paul lover Tele-Holic

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    I've had really sqealy ECC83 be totally quiet in the PI slot.
     
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