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    Microphone power hum on W520

    Discussion in 'Lenovo' started by andy789, May 24, 2012.

  1. andy789

    andy789 Notebook Consultant

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    Hi All,

    Today I have noticed a terrible ground noise (hum) when recording with my MMX300 Beyerdynamic. It disappears completely when running on battery. Also, touching any metal parts on the laptop helps a lot.

    How can I get rid of it? Did someone try USB isolators like this one?

    USB Isolator, Galvanic Isolated USB 2.0 - Electronics-shop.dk

    Other suggestions?

    Thanks!
     
    andy789, May 24, 2012
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  2. Colonel O'Neill

    Colonel O'Neill Notebook Deity

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    I get a hum on AC on my headphones in the headphone jack as well. Also disappears on battery and also disappears when I ground the laptop physically.

    I have a 2-prong adapter, and assume you do as well. Maybe a 3-prong adapter will be sufficient?
     
    Colonel O'Neill, May 24, 2012
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  3. Thors.Hammer

    Thors.Hammer Notebook Enthusiast

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    Thors.Hammer, May 24, 2012
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  4. andy789

    andy789 Notebook Consultant

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    I am thinking about a few options:

    1) USB isolator
    2) connecting mic jack via some cheap ground loop isolator (even though I don't experience a ground loop)

    I do have a 2-prong power adapter on W520 and another 3-prong on my second Dell laptop. The hum is the same.

    Other suggestions?
     
    andy789, May 24, 2012
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  5. andy789

    andy789 Notebook Consultant

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    I was about to start ordering USB or mic isolators, but this 60Hz humming noise all disappeared suddenly. I've tested it on different laptops and even different headsets. Cannot heart it anummore.

    it looks as it was related to my home power system... cannot identify what was causing the hum.
     
    andy789, May 29, 2012
    #5