Audio coupling/decoupling caps with higher capacitance than their rated values

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  • PCBONEZ
    Grumpy Old Fart
    • Aug 2005
    • 10661
    • USA

    #21
    Re: Audio coupling/decoupling caps with higher capacitance than their rated values

    Originally posted by lti
    If those caps were required, they would have been in the application circuit in the datasheet for that IC.
    Not true.

    Originally posted by lti
    The 0.22uF caps were connected between the audio signal and ground in a tone control circuit.
    If they were connected to ground they were not coupling caps.
    Try EMI filter.
    .
    Mann-Made Global Warming.
    - We should be more concerned about the Intellectual Climate.

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    Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.

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    Comment

    • lti
      Badcaps Legend
      • May 2011
      • 2557
      • United States

      #22
      Re: Audio coupling/decoupling caps with higher capacitance than their rated values

      I measured 0.0001V across the coupling caps with no input source, and that multimeter gives unusually high voltage readings (unless the other two I have used give low readings). Even if they forgot the coupling caps in the application circuit, it still doesn't need them.

      I never said the 0.22uF caps were coupling caps.

      Comment

      • Logistics
        Badcaps Veteran
        • Apr 2007
        • 721
        • USA

        #23
        Re: Audio coupling/decoupling caps with higher capacitance than their rated values

        Maybe I missed something, are the .22uF's between the audio-in connectors and the audio-in pins of the IC? Last time I saw this the datasheet said it was to remove any scratchy sounds which may result from cheap volume potentiometers. However, those caps were in-line or rather they continued the circuit, they were not tied to ground like a filter-cap.
        Presonus Audiobox USB, Schiit Magni 3, Sony MDR-V700

        Comment

        • PCBONEZ
          Grumpy Old Fart
          • Aug 2005
          • 10661
          • USA

          #24
          Re: Audio coupling/decoupling caps with higher capacitance than their rated values

          It's still a filter cap of some kind even if the drain side isn't at ground.

          At this point I'm content to let him have the scratchy sound.
          .
          Mann-Made Global Warming.
          - We should be more concerned about the Intellectual Climate.

          -
          Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.

          - Dr Seuss
          -
          You can teach a man to fish and feed him for life, but if he can't handle sushi you must also teach him to cook.
          -

          Comment

          • lti
            Badcaps Legend
            • May 2011
            • 2557
            • United States

            #25
            Re: Audio coupling/decoupling caps with higher capacitance than their rated values

            Originally posted by Logistics
            Maybe I missed something, are the .22uF's between the audio-in connectors and the audio-in pins of the IC? Last time I saw this the datasheet said it was to remove any scratchy sounds which may result from cheap volume potentiometers. However, those caps were in-line or rather they continued the circuit, they were not tied to ground like a filter-cap.
            These caps are connected between the audio input and ground.
            Originally posted by PCBONEZ
            At this point I'm content to let him have the scratchy sound.
            I didn't want this thread to get this long when I started it. I have no problems with scratchy sound.

            Comment

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