Fender amp Tube question - Please help!!

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by supergiant, Aug 30, 2006.

  1. supergiant

    supergiant Member

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    I'm hoping someone will know this since i cannot seem to get a straight answer from anyone locally ... i'm wondering if it is ok to swap a 12ax7 for the 12at7 phase inverter tube in the preamp section of my '71 bassman 100 head.

    I tried it and it sounds really good but I don't want to fry the amp.

    I am running 5881 power amp tubes, 2 12ax7s in the preamp and there is a 12at7 in the PI.

    I just want to know if it's ok to go all 12ax7s???
     
  2. brad347

    brad347 Member

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    it will be fine.
     
  3. stonewolf

    stonewolf Member

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    I have done this in a mesa mark 2c+ and never had a problem, supposedly the at7 is a stronger tube from what I recall.
     
  4. rockon1

    rockon1 Member

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    Generally speaking its OK to go with a lower gain tube such as a 12AT7 in place of a higher gain 12AX7. I would be more cautious about putting a higher gain tube 12AX7 in place where a lower gain tube goes.(if in fact it calls for a 12AT7)
     
  5. bob-i

    bob-i Member

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    That's just fine. You'll get earlier breakup and more drive. If that's what you like then the 12AX7 is the right tube for you.
     
  6. SteveStrat

    SteveStrat Member

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    I second that........Won't hurt the amp a bit. I've swapped 12at7s and 12ax7s many times in my '66 Bassman.

    Steve
     

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