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    VTA ST-70 impedance question.

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    hrudu90

    Posts : 26
    Join date : 2011-01-02

    VTA ST-70 impedance question.

    Post by hrudu90 on Fri Jan 09, 2015 1:26 am

    How to figure out the impedance of a VTA ST-70?

    I bought the amp used and it has only one speaker tab in the back.
    It does sound great pushing a pair Cornwalls (8ohm?) using a PAS3 as pre-amp, BTW restored by Sal.

    So, can I hook up some 4ohm speakers to the combo above?

    Thank you
    Gin

    peterh

    Posts : 643
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: VTA ST-70 impedance question.

    Post by peterh on Fri Jan 09, 2015 3:49 am

    You will have to open it up ( from bottom) and identify the cables coming out from the output tranny.
    Someone has made the decision that onle one outlet should be used, the original st-70 has a
    outlet with ground 4 8 and 16 ohms connectors. You can buy these at dynacokitparts and
    replace the 2-pole you have.

    At the inside identify the 4 cables from the output tranny, they are color coded as :
    ground = black
    brown = 4 ohm
    orange = 8 ohm
    yellow = 16 ohm ( this is also hardwired to the circuit board as this is the feeback signal.

    If you want 4 ohm output, then connect the black and brown to the existing outlets .

    See the manual downloadablle at this site.


    hrudu90

    Posts : 26
    Join date : 2011-01-02

    Re: VTA ST-70 impedance question.

    Post by hrudu90 on Fri Jan 16, 2015 6:08 pm

    Thank you.

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