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    What is the bias setting the the ST-70 Kit?

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    Mike16W

    Posts: 37
    Join date: 2009-11-03

    What is the bias setting the the ST-70 Kit?

    Post by Mike16W on Wed Mar 02, 2011 3:08 pm

    I have one the ST-70 kit running the Golden Lions KT-66 tubes. I have misplaced my manual. Bob was good enough to send me the schematic but now I want to check the bias and don't have the figures. Can someone tell me what the bias setting should be when taken from the front tube sockets.

    Thanks
    Mike

    Mike16W

    Posts: 37
    Join date: 2009-11-03

    Re: What is the bias setting the the ST-70 Kit?

    Post by Mike16W on Wed Mar 02, 2011 3:19 pm

    And the test points and which pot to adjust. Sorry for all the questions.

    Mike

    Bob Latino
    Admin

    Posts: 1997
    Join date: 2008-11-26
    Location: Massachusetts

    Re: What is the bias setting the the ST-70 Kit?

    Post by Bob Latino on Wed Mar 02, 2011 3:58 pm

    Hi,

    EL34's are biased at .40 VDC on the VTA ST-70 amp kit. On the Gold Lion KT66 you can go up to .45 VDC per tube.

    For all VTA ST-70 KITS > The test point for the front tube on each side is the hole on the front tube socket that says "Biaset 1.56V". Measure there and turn the bias pot on the driver board next to the FRONT tube. For biasing the rear tube use the hole opposite that hole and use the rear bias pot to bias the rear tube on each channel.

    If you have a wired and tested amp from me then the rear tube bias measuring point is on a different hole on the front tube socket.

    Bob

    Mike16W

    Posts: 37
    Join date: 2009-11-03

    Re: What is the bias setting the the ST-70 Kit?

    Post by Mike16W on Wed Mar 02, 2011 4:09 pm

    Thanks Bob for your help.

    Mike

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