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    Upgrade VTA ST70 to ST120?

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    polarflux

    Posts : 49
    Join date : 2010-02-12
    Location : Alaska

    Upgrade VTA ST70 to ST120?

    Post by polarflux on Sun Feb 26, 2017 7:02 pm

    What would I have to do to upgrade my VTA ST70 to a 120. New power tranny, add the power supply under the hood. Isn't there a second choke as well? What else. I have the burly chassis so I would be good to go there. Sort of the reason I'm interested is that I prefer running KT88's. The amp would run cooler and I would have some extra juice to run less efficient speakers. Worth the $? Has anybody else done this?
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    arledgsc

    Posts : 454
    Join date : 2012-11-30
    Location : SF Bay CA

    Re: Upgrade VTA ST70 to ST120?

    Post by arledgsc on Mon Feb 27, 2017 10:27 am

    I would be inclined to say not worth it unless you also change output transformers plus the 2nd choke to take advantage of the extra power capability of the ST120 power tranny.
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    corndog71

    Posts : 553
    Join date : 2013-03-19
    Location : It can get windy here

    Re: Upgrade VTA ST70 to ST120?

    Post by corndog71 on Mon Feb 27, 2017 11:05 am

    Or you can try to sell your ST70 so someone else can enjoy it while you buy a new ST120.
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    Peter W.

    Posts : 434
    Join date : 2016-08-07
    Location : Melrose Park, PA

    Re: Upgrade VTA ST70 to ST120?

    Post by Peter W. on Mon Feb 27, 2017 11:26 am

    corndog71 wrote:Or you can try to sell your ST70 so someone else can enjoy it while you buy a new ST120.

    Best advice yet!
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    polarflux

    Posts : 49
    Join date : 2010-02-12
    Location : Alaska

    Re: Upgrade VTA ST70 to ST120?

    Post by polarflux on Mon Feb 27, 2017 1:26 pm

    I was wondering if the output tranny's were different. For some reason I thought the st120 also used an a440, or whatever the vta st70 used. With that, yep, would be better to start fresh with a new build.
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    Bob Latino
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    Join date : 2008-11-26
    Location : Massachusetts

    Re: Upgrade VTA ST70 to ST120?

    Post by Bob Latino on Mon Feb 27, 2017 2:42 pm

    corndog71 wrote:Or you can try to sell your ST70 so someone else can enjoy it while you buy a new ST120.

    This is the best advice ... The three transformers are different and I do not sell the ST-120's transformers separate from the amp kit. If you can sell your (now wired) VTA ST-70, you may be able to get enough funds to purchase the KIT version of the ST-120.

    Bob

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