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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


3 posters

    12AU7W / 6189 Hum

    jimmeq
    jimmeq
    jimmeq


    Posts : 60
    Join date : 2017-02-24
    Location : Six Miles West of Jiminy Peak Ski Resort
    • Post n°1

    12AU7W / 6189 Hum Empty 12AU7W / 6189 Hum

    Post by jimmeq Thu Jul 19, 2018 3:26 pm

    In my Distortion & Hum post I mention the hum was (is) created by the Tung-Sol tubes.

    I exchanged the center driver tube one by one and each new production Tung-Sol 12AU7W / 6189 introduced a very noticeable hum even with the volume turned down. This is not a slight against Tung-Sol...

    They are on the compatible "list".

    Three bad tubes? Really?? affraid

    I can exchange them; I just find it very strange I'd get three bad new tubes.

    Anybody else experience anything like this even with other tube brands?

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    corndog71
    corndog71
    corndog71


    Posts : 840
    Join date : 2013-03-19
    Location : It can get windy here
    • Post n°2

    12AU7W / 6189 Hum Empty Re: 12AU7W / 6189 Hum

    Post by corndog71 Thu Jul 19, 2018 3:32 pm

    jimmeq wrote:In my Distortion & Hum post I mention the hum was (is) created by the Tung-Sol tubes.

    I exchanged the center driver tube one by one and each new production Tung-Sol 12AU7W / 6189 introduced a very noticeable hum even with the volume turned down. This is not a slight against Tung-Sol...

    They are on the compatible "list".

    Three bad tubes?  Really?? affraid

    I can exchange them; I just find it very strange I'd get three bad new tubes.

    Anybody else experience anything like this even with other tube brands?


    Dare I ask, who did you buy them from?
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    peterh
    peterh
    peterh


    Posts : 1832
    Join date : 2012-12-25
    Location : gothenburg, sweden
    • Post n°3

    12AU7W / 6189 Hum Empty Re: 12AU7W / 6189 Hum

    Post by peterh Thu Jul 19, 2018 3:50 pm

    jimmeq wrote:In my Distortion & Hum post I mention the hum was (is) created by the Tung-Sol tubes.

    I exchanged the center driver tube one by one and each new production Tung-Sol 12AU7W / 6189 introduced a very noticeable hum even with the volume turned down. This is not a slight against Tung-Sol...

    They are on the compatible "list".

    Three bad tubes?  Really?? :affraid:

    I can exchange them; I just find it very strange I'd get three bad new tubes.

    Anybody else experience anything like this even with other tube brands?

    I had some kind of similar experience with 5963 tubes. I junked them and installed
    JJ ECC82 instead, and the amp is dead quiet and have been about 1000h .

    It's not uncommon to have filament <> cathod leakage
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    jimmeq
    jimmeq
    jimmeq


    Posts : 60
    Join date : 2017-02-24
    Location : Six Miles West of Jiminy Peak Ski Resort
    • Post n°4

    12AU7W / 6189 Hum Empty Re: 12AU7W / 6189 Hum

    Post by jimmeq Fri Jul 20, 2018 1:37 pm

    corndog71 wrote:
    jimmeq wrote:In my Distortion & Hum post I mention the hum was (is) created by the Tung-Sol tubes.

    I exchanged the center driver tube one by one and each new production Tung-Sol 12AU7W / 6189 introduced a very noticeable hum even with the volume turned down. This is not a slight against Tung-Sol...

    They are on the compatible "list".

    Three bad tubes?  Really?? affraid

    I can exchange them; I just find it very strange I'd get three bad new tubes.

    Anybody else experience anything like this even with other tube brands?


    Dare I ask, who did you buy them from?


    Tube Depot.
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    • Post n°5

    12AU7W / 6189 Hum Empty Re: 12AU7W / 6189 Hum

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