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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


    Dynaco PAS-3 rear panel replacement

    ViperZ
    ViperZ

    Posts : 100
    Join date : 2010-03-26

    Dynaco PAS-3 rear panel replacement Empty Dynaco PAS-3 rear panel replacement

    Post by ViperZ on Sat Mar 14, 2020 10:50 pm

    Decided to replace the rear RCA connectors on my PAS-3.

    I bought the kit from dynakitparts - https://www.dynakitparts.com/shop/pas-rca-jack-kit/

    The question I have is - dynakitparts Output ground is directly connected to the rest of the ground plane, whereas in the original design it was separated by 10-Ohm resistors. Should I cut the ground traces on the board, and install the 10-Ohm resistors?

    Thank you.

    Photo here: https://photos.app.goo.gl/TFbWa2S2nft1TY3WA
    ViperZ
    ViperZ

    Posts : 100
    Join date : 2010-03-26

    Dynaco PAS-3 rear panel replacement Empty Re: Dynaco PAS-3 rear panel replacement

    Post by ViperZ on Mon Mar 16, 2020 12:26 am

    I installed dynakitparts backplane as is, without 10-ohm resistors between grounds. Everything works great.
    Now need to figure out how to update the phono wiring, since it starts humming (without music) at around 1 o'clock on the volume dial.
    ViperZ
    ViperZ

    Posts : 100
    Join date : 2010-03-26

    Dynaco PAS-3 rear panel replacement Empty Re: Dynaco PAS-3 rear panel replacement

    Post by ViperZ on Thu Mar 19, 2020 3:48 pm

    Opened PAS-3 again. Phono used to hum starting at around 12-1 o'clock. Now after I removed loudness taps from volume and replaced rear panel, it starts humming at 10 o'clock...

    What I am doing now: I will disconnect phono grounds from main grounds (remove jumpers). So now two black wires coming off each channel on phono board will go to 'dedicated' negative on its own channel on the back panel.
    I will also twist right/left phono wires between inputs and selector to see if it helps.

    Any help on how to improve on this hum would be very helpful. Thank you!

    Here is a photo of updated wiring so far: https://photos.app.goo.gl/BcwwspGBXD2Luxm39

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    Dynaco PAS-3 rear panel replacement Empty Re: Dynaco PAS-3 rear panel replacement

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      Current date/time is Fri Apr 10, 2020 7:59 am