Nutube Mini Major

Discussion in 'Building the Classics' started by JKrauland, May 3, 2018.

  1. JKrauland

    JKrauland New Member

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    Hey everyone,
    So I've been checking these nutubes out and I had the idea to use them to make a really compact mini major. I've always wanted a major but couldnt afford a legit one, not to mention it's way too powerful. Do you think this is possible? Also if anyone knows where to find a schematic for a mini major i'd be eternally grateful. I'm not too hip to amp building, I mostly do luthiery stuff so I'm not quite savvy enough to convert the original marshall schematic to what I'm talking about.

    Thanks a bunch
     
  2. ampmadscientist

    ampmadscientist Well-Known Member

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    From what I understand, Nutubes are extremely microphonic.
    The Nutube requires a switching power supply (DC to DC converter) to run the florescent "filament?"

    For a person who does not build amplifiers, it could be a formidable challenge.

    But don't forget, Philo T. Farnsworth.
    He knew nothing whatsoever about electronics, and 20 years later he invented television. He simply "did it," despite that such a thing was widely regarded as impossible - he never gave up.

    Drawing inspiration from Philo, (and I hope you will) be sure that determination and perseverance make the impossible possible.
     
  3. Copperheadroads

    Copperheadroads Active Member

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    Microphonic ? as a pickup winder Send the Nutubes to me & I will wax pot them for you .
     
  4. ampmadscientist

    ampmadscientist Well-Known Member

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    You will need more than wax to fix that issue.

    Check out the microphonics test at 14:14.
    Remember that the nutube has a maximum gain of: 5.

     
    Last edited: May 6, 2018
  5. Copperheadroads

    Copperheadroads Active Member

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    I've have fixed dozens of microphonic Gibson pickups without potting them .you Just need to know how to do it . Fenders on the other hand should be potted .
     
  6. ampmadscientist

    ampmadscientist Well-Known Member

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    Dude,
    this thing starts ringing just by laying your hand on the test bench....:agreed:

    It would take 3X nu tube sections to equal the gain of 1X 12AX7.
    But nu tube has voltage limit which is less than 1/3 of vacuum tube.

    In other words: replacing preamp tube with nu tubes would be pretty challenging. I'm not saying impossible.
     
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