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    KT120 Bias



    Posts : 22
    Join date : 2008-12-22

    KT120 Bias

    Post by merlot on Wed Aug 03, 2011 8:48 am

    I just bought some KT120s for my ST-120. Parts Connexion had a 20% off sale...

    I see from the various threads on this site that people have been biasing their KT120s in an ST-120 at anywhere from 55ma to 75ma. Just wondering if a consensus has evolved with respect to the "most appropriate" level?


    Bob Latino

    Posts : 2382
    Join date : 2008-11-26
    Location : Massachusetts

    Re: KT120 Bias

    Post by Bob Latino on Wed Aug 03, 2011 10:07 am


    I did originally bias the Tung-Sol KT120 up to 75 milliamps per tube in the ST-120. They played fine in the ST-120 @ 75 milliamps per tube - BUT - after careful listening I did not find the KT120's to sound any better @ 75 milliamps than 55 milliamps. My recomendation is to bias those tubes @ 55 milliamps per tube in the ST-120. This bias setting will give optimum sound and long tube life.


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