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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


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    vt st70 socket pin question

    rymi
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    rymi


    Posts : 21
    Join date : 2017-05-20
    • Post n°1

    vt st70 socket pin question Empty vt st70 socket pin question

    Post by rymi Mon Jul 24, 2017 8:36 pm

    I put together the VTA ST70 kit a few months ago. Went well but one step kind of bothers me in regards to the socket pins. I don't recall the specifics nor do I have the instructions in front of me but....

    The step was connecting a resistor lead thru one pin and into another... I believe they were connected to the bias sockets.

    In order to make this connection cleanly I slightly bent/twisted the pin in question on each socket. I think instructions may have even said to bend or twist this pin.

    Do you recall what I am trying to describe?

    And if I am making sense, are these pins/sockets robust enough to bend and twist in the manner and not worry that I fatigued the pins or risked and intermittent connection?
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    Bob Latino
    Bob Latino
    Bob Latino
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    Posts : 3262
    Join date : 2008-11-26
    Location : Massachusetts
    • Post n°2

    vt st70 socket pin question Empty Re: vt st70 socket pin question

    Post by Bob Latino Tue Jul 25, 2017 5:56 pm

    rymi wrote:I put together the VTA ST70 kit a few months ago. Went well but one step kind of bothers me in regards to the socket pins.  I don't recall the specifics nor do I have the instructions in front of me but....

    The step was connecting a resistor lead thru one pin and into another... I believe they were connected to the bias sockets.

    In order to make this connection cleanly I slightly bent/twisted the pin in question on each socket. I think instructions may have even said to bend or twist this pin.

    Do you recall what I am trying to describe?

    And if I am making sense, are these pins/sockets robust enough to bend and twist in the manner and not worry that I fatigued the pins or risked and intermittent connection?

    Yes - On the VTA ST-70 and ST-120 there is a wire that goes from each of the four bias measuring points on the front tube sockets to pins 1 and 8 of each of the four output tube sockets. You then use a 10 ohm 2 watt resistor to run from pin #8 to the ground lug on that tube socket. This gives that tube in the socket a reference to chassis ground. How the pins on the tube socket are bent is of no real concern. Some amp builders like to bend each pin back a little to keep each pin connection a little bit further away from the next pin. The bending back of the pin is not really necessary. The instructions in the manual do say to twist the two pins a little so the solder holes in the pins will line up and make it easier to run a wire between the two pins.

    Bob
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