The Dynaco Tube Audio Forum

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


    non-polarized electrolytics

    Share

    j beede

    Posts : 328
    Join date : 2011-02-07
    Location : California

    non-polarized electrolytics

    Post by j beede on Thu Feb 17, 2011 10:42 pm

    So what is the current thinking with respect to using polarized versus non-polarized electrolytics? In particular I am talking about the 50µF, 75V caps in the Mark III bias generator.
    ...j

    GP49

    Posts : 735
    Join date : 2009-04-30
    Location : East of the sun and west of the moon

    Re: non-polarized electrolytics

    Post by GP49 on Fri Feb 18, 2011 1:00 pm

    There is no point in doing that. The bias circuit operates at constantly negative voltage. Barring malfunction it does not go positive, so conventional electrolytics work just fine (if one does not wire them with the negative side grounded -- a mistake I have seen more than a few hobbyists do).

    j beede

    Posts : 328
    Join date : 2011-02-07
    Location : California

    Re: non-polarized electrolytics

    Post by j beede on Fri Feb 18, 2011 1:15 pm

    Yes. I didn't mean from an electrical necessity point of view, I meant from stability and reliability points of view. My local vendor's stock of 47µF, 100V caps are non-polarized and I have not used them before. I'll visit the Sprague web-site to get educated on NP electrolytics.
    ...j

    GP49

    Posts : 735
    Join date : 2009-04-30
    Location : East of the sun and west of the moon

    Re: non-polarized electrolytics

    Post by GP49 on Sat Feb 19, 2011 1:05 am

    Your local vendor's nonpolarized electrolytics are likely meant for loudspeaker crossovers, which is an AC application requiring nonpolar capacitors. The DC power supplies in Dynaco amplifiers do not.

    Sponsored content

    Re: non-polarized electrolytics

    Post by Sponsored content Today at 4:48 am


      Current date/time is Sat Dec 10, 2016 4:48 am