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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 products

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    Quad Cap Question for ST-70


    Posts : 17
    Join date : 2014-03-21

    Quad Cap Question for ST-70 Empty Quad Cap Question for ST-70

    Post by litefootdan Wed Nov 16, 2022 7:17 pm

    Hi All,
    I'm hoping you guys may be able to help clarify something for me.  I have and ST-70 that I've decided to upgrade with the tubes4hifi "classic" board.  I thought it would be a nice time to replace the quad cap while I'm in there.  I removed the wires connected to the cap sections and labeled them accordingly to their sections.  Then I installed my new quad cap in the same orientation that the old one that was removed was.  I re-soldered the wires and thought everything was dandy.  I had printed the wiring diagram from the tubes4hifi site so that I could remove the 6.8k and 22k resistors and add the appropriate resistor between tabs 3 and 4.  Everything looked peachy until I noticed the picture of the orientation of the quad cap on the website.  The can orientation on my amp has the "square" facing the PCB, while the can orientation of the quad cap on the website pic has the "triangle" facing the PCB.  My question is how bad an error have I made.  Do I need to rewire everything.  I sure hope you guys can help me sort this out.  Thanks in advance for any help offered.
    I'm sorry, I thought I could insert an image but I don't have any images on the web for me to insert a url....    If anyone wants to have a look at what I've done to my mess of an amp I could text pictures....

    Posts : 1779
    Join date : 2008-11-30

    Quad Cap Question for ST-70 Empty Re: Quad Cap Question for ST-70

    Post by tubes4hifi Tue Nov 22, 2022 2:40 pm

    with the upgraded quad cap the triangle should face the PCB.
    The upgraded quad cap has an 80uF section that must NOT be connected directed to the rectifier tube.
    Diagram below is supplied with every quad cap that I send out . . . .
    Quad Cap Question for ST-70 80-40-30-20quadST70

      Current date/time is Sat Nov 26, 2022 9:53 am