The Dynaco Tube Audio Forum

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The Dynaco Tube Audio Forum

Dedicated to the restoration and preservation of all original Dynaco tube audio equipment - Customer support for Tubes4hifi VTA tube amp and preamp kits and all Dynakitparts.com products


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    Dynaco PAS 3 Hum

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    breading

    Posts : 39
    Join date : 2010-01-08

    Dynaco PAS 3 Hum Empty Dynaco PAS 3 Hum

    Post by breading Fri Oct 08, 2021 2:26 pm

    I have a hum that is constant and not affected by the volume control.  Both channels, all sources.  What is the appropriate sequence for tracing this issue?  I have check all voltages and they match the spec sheet.  Also checked the tubes with my Hickok and they test good.  Any help will be appreciated.
    tubes4hifi
    tubes4hifi
    Admin

    Posts : 1709
    Join date : 2008-11-30

    Dynaco PAS 3 Hum Empty Re: Dynaco PAS 3 Hum

    Post by tubes4hifi Fri Oct 08, 2021 9:08 pm

    most likely the power supply, and possibly just the rectifier tube.
    Get a new rectifier tube (12X4) and replace the old one.
    If that doesn't cure the problem, get a new power supply board, that makes a huge difference in the quality of the PAS3.
    Well worth the $54 or so,
    https://www.erhard-audio.com/Power_Supply_Kits.html

      Current date/time is Tue Oct 19, 2021 8:04 am