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Thread: Koch Power Transformer

  1. #1
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    Koch Power Transformer

    Hello!

    I have repair a Koch Jupiter 45 a month ago. The amp came with the transformer HT tap with only 10VAC ( it should be 250VAC ).

    This amp has two 12ax7 on the pre amp section and two mosfets on the power section.

    I have send an email requesting a quote for the transformer and since they didnt bother answer me i send it to a shop for a rewinding.

    After one month playing with it, the same thing as happen again. this time 50VAC on the HT so i send it again for repair.

    My question is;
    Do you think the circuit has a fault that is pulling a large amont of current of the transformer?
    Or it was just a bad winding?

    Thanks

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  2. #2
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    i guess there is a fault in the power section and there is not an adequate protection via fuse or other.
    When powering an amp you have to apply voltage gradually and monitor current.

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  3. #3
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    The voltage was applied gradually and everything was fine during a month playing.

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  4. #4
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    two mosfets on the power section
    I mean, on the output section

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