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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


    Finished My First Dyna / VTA ST-70 Upgrade

    knotscott
    knotscott

    Posts : 34
    Join date : 2019-12-28
    Location : Rochester, NY

    Finished My First Dyna / VTA ST-70 Upgrade Empty Finished My First Dyna / VTA ST-70 Upgrade

    Post by knotscott on Sun Jan 19, 2020 10:05 pm

    This was a Dynakit ST-70 built by my uncle in 1964. He used it for many years, and gave it to me sometime in the late 80s. In the early 90s I bought another 1961 factory wired version of the same amp, and used both amps as mono blocks in my stereo system for some 25 years.  Both amps were wired for triode, and we beefed up the filter caps.  

    A few years ago they started to act their age, so I pulled them out of service to give them some love.  The 1964 model built by uncle is now done.  I stripped it down, gave it a good cleaning, added a new VTA circuit board, all new tubes, upgraded the inputs and speaker jacks, replaced the quad cap with the Authenticap that Bob recommended, added new power cord, and wired it all back up.  Shortly after, I added the toggle switches for triode/pentode switching.  I also added an "on" light between the switches to help my wife remember to it off! :-D  

    Now to go after the factory wired ST-70 and get some new tubes for my old Lazarus Cascade Basic preamp!




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    Finished My First Dyna / VTA ST-70 Upgrade Vta210
    Finished My First Dyna / VTA ST-70 Upgrade Vta610

      Current date/time is Mon Oct 26, 2020 6:23 pm