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Thread: A question for the Senior Dreambuster

  1. #1
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    Default A question for the Senior Dreambuster

    After a year long search, I finally pulled the trigger on a 2902. While I'm impatiently waiting for it to arrive, a question struck my head: how bad can a poorly conditioned power supply affect its operation?

    We have pretty bad power in our rehearsal room, especially in the winter time, when the power goes as low as 180V (Europe). I know lower voltage affects tone, but can this harm the unit in any way?

    Thanks!

  2. #2
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    180 is way too low. Normal voltage tolerance is +/- 10% @ 240V, so 216-265. Inside the amp, that translates to a +/- 10% variation on the plate, bias and filament voltages.

    The filament voltage is the biggest concern because if too low, will cause premature aging on the power tubes. Filament voltage @ 240 is 12.6VAC. At +/- 10% that's 11.3-13.86. At 180V, your filament voltage will be down 25% or 9.45. You need to keep the amp at minimum 216V or you'll be burning though KT88s.
    Dave Phelge
    Chief Misconception Eradicator
    support@fryette.com

    "We are what we pretend to be, so we must be careful what we pretend to be". - Kurt Vonnegut

  3. #3
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    Ok, thank you very much!

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