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    VTA ST-70 turn on noise



    Posts : 40
    Join date : 2010-02-12

    VTA ST-70 turn on noise

    Post by polarflux on Mon Apr 05, 2010 3:10 pm

    I don't know if this is normal, when I turn on my ST-70 and as the tubes warm up (approximately the first 3-45 seconds) there is an audible buzz coming out of the speakers. It does not concern me much, but I am interested why this might be happening. Is the noise perhaps due to the bias currents in the power tubes being out of balance as the tubes warm? I notice the same sort of noise (but not as loud) when the biases are intentionally set out whack.


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