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    Bias voltage for KT88s on an ST-70

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    polarflux

    polarflux

    Posts: 29
    Join date: 2010-02-12
    • Post n°1

    Bias voltage for KT88s on an ST-70

    Post by polarflux on Thu Feb 18, 2010 3:50 pm

    What should the bias be set to when using KT 88's?
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    Bob Latino

    Bob Latino
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    Posts: 1544
    Join date: 2008-11-26
    Location: Massachusetts
    • Post n°2

    Re: Bias voltage for KT88s on an ST-70

    Post by Bob Latino on Thu Feb 18, 2010 4:08 pm

    First of all in an ST-70 you must have an upgraded power transformer (which you do) to run KT88's. KT88's use about 35% more current than an EL34 and can damage the power transformer in an original ST-70 with a stock PA-060 power transformer.

    Bias KT88's at .500 VDC in any VTA boarded ST-70 with an upgraded power transformer.

    Bob
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