Please help! Noise in audio line

Discussion in 'The Projects Forum' started by luisnperez, Aug 23, 2013.

  1. luisnperez

    Thread Starter New Member

    Aug 23, 2013
    4
    0
    Every time I build an audio project I get an electric noise or a long beep on the audio output like the headphone out. This time Im working with an MP3 player that requires a 100uf capacitor in series with the line out. The noise is annoying?
    Whats the problem? Grounding? Need to add extra components?
    This is the mp3 im using
    http://www.elechouse.com/elechouse/images/product/USB-SD MP3 Modules/WT9501M03.pdf

    The circuit is on the pdf file at the bottom.
    The noise is a noise! Like a long beep
    Thanks!
     
    Last edited: Aug 23, 2013
  2. crutschow

    Expert

    Mar 14, 2008
    12,981
    3,221
    My car has a noisy engine. What's the problem? :rolleyes:

    Like that question I can't answer yours without more info.---

    What type of noise are you having?

    Show a diagram of how you are connecting it.
     
  3. luisnperez

    Thread Starter New Member

    Aug 23, 2013
    4
    0
    mp3 circuit
    wt9501.JPG
     
  4. MrChips

    Moderator

    Oct 2, 2009
    12,418
    3,355
    Your 5V supply is noisy.
     
  5. luisnperez

    Thread Starter New Member

    Aug 23, 2013
    4
    0
    Thanks Mr chips! So if is 5v power supply which one do I need that will not make noise?
    Crutschow I did post the circuit is very simple and the noise is like a beep I told you many times.
     
  6. MrChips

    Moderator

    Oct 2, 2009
    12,418
    3,355
    To test if noise is coming from the power supply, replace the power supply with a battery.
     
  7. apprenticemart2

    Member

    May 7, 2013
    67
    7
    Can we hear a recording of the noise just in case it's some kind of feedback you're hearing?
     
  8. luisnperez

    Thread Starter New Member

    Aug 23, 2013
    4
    0
    OK so what I learn is that never connect the audio ground to the power supply ground (-) it will make a noise. The audio ground must be connecter to the GND of the audio source (mp3 player, mixer board...).
    I know is an onvious thing to do for you guys but it wasn't for me.
    Thank you all!
    Luis
     
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