Why aren't toroidal power transformers more common in tube amps?

Discussion in 'Amp Tech Center' started by Golem, Dec 12, 2019.

  1. Golem

    Golem Tele-Holic Silver Supporter

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    I have a tube amp with them and it definitely contributes to weight savings. It makes me wonder why this isn't more common. I can tell you it doesn't make the amp sound any worse.
     
  2. kbold

    kbold Tele-Afflicted Silver Supporter

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    The main advantages of toroidals are weight savings and efficiency.
    Toroidals are not often seen in valve amps. The cost is probably one factor: toroids are more expensive.
    Also, isolation is far easier on an EI transformer, with separate bobbins for primary and secondary.
    (You don't want the primary stuff coming out the other side.)

    Also, a toroidal transformer looks very modern, so the aesthetics in a valve amp .....

    For me, the user, the higher safety of improved isolation trumps other issues.
     
    Golem and ponce like this.
  3. Golem

    Golem Tele-Holic Silver Supporter

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    I think they give off a more vintage Tesla (the inventor not the car) kind of vibe. It's crazy how light my Mills Custom is.
     
  4. zook

    zook Friend of Leo's

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    I've used them a couple times on one-offs. They take up more space than the traditional type though.
     
  5. Paul G.

    Paul G. Friend of Leo's

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    Most likely the price.
     
  6. vanr

    vanr Tele-Afflicted

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    I had a Hughes & Kettner that had a torroidal PT in it. OT also I believe.
     
  7. LightningPhil

    LightningPhil Tele-Meister

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    There's more capacitive coupling through toroidal transformers unless a good screen is used.

    But should be slightly more efficient, lighter and have way less stay field.

    So no reason not to user them other than availability and cost.
     
  8. printer2

    printer2 Poster Extraordinaire

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    Price and tradition. If you are going to go different, go switch-mode power supply, get rid of the big hunk of iron and its weight. On home built, I have a toroidal sitting on the shelf.
     
  9. LightningPhil

    LightningPhil Tele-Meister

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    Switch mode would be awesome. Nice clean DC for filaments and adjustable voltage for power scaling.
     
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