Choosing the appropriate type of capacitor/resistor for audio amp. (TDA2822M)

Discussion in 'The Projects Forum' started by TheLaw, Sep 27, 2010.

  1. TheLaw

    Thread Starter Member

    Sep 2, 2010
    228
    2
    Hi,

    I am going to start a simple amp project. I am also in the market for a sound card for my computer. I was looking around and saw an Asus card that used Nichicon KZ Audio Capacitors.

    So, seeing those made me wonder what made an "audio capacitor" different than a regular old electrolytic. Oh and the KZs are electrolytics.

    [​IMG]

    So I was wondering what difference these capacitors have with a general purpose electrolytic and where in an amplifier would they be most suitable?

    Here's the circuit I am working on:

    [​IMG]

    So what does it all mean?

    Thanks.
     
    Last edited: Sep 28, 2010
  2. marshallf3

    Well-Known Member

    Jul 26, 2010
    2,358
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    Thy're all common components, C1 - 5 are electrolytics, 6 & 7 could be 50 or 100V film or ceramic disc caps. C1 & 2 could be about any voltage but C3 - 5 should be somewhere above the supply voltage in rating.

    Common 1/4W resistors as well, 5% or better tolerance suggested.
     
  3. TheLaw

    Thread Starter Member

    Sep 2, 2010
    228
    2
    Thanks! I just wasn't sure exactly where the film caps would go into play there.
     
  4. TheLaw

    Thread Starter Member

    Sep 2, 2010
    228
    2
  5. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
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    If you need a high capacity in a small package, like for a power supply filter.
     
  6. TheLaw

    Thread Starter Member

    Sep 2, 2010
    228
    2
    I still don't quite get it. If its an audio cap, shouldn't it be used where audio is physically present. Not necessarily a power supply cap? Or is that part of it?
     
  7. marshallf3

    Well-Known Member

    Jul 26, 2010
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    Naw, it's just a high quality (and probably high$) capacitor. Typically this will mean a tighter value tolerance and lower ESR. Something you might find in a $2,000 receiver but not driving a simple stereo IC such as you presented earlier.
     
  8. TheLaw

    Thread Starter Member

    Sep 2, 2010
    228
    2
    Well the funny thing is, is that they are dirt cheap. Like $0.70 for a 470uf 50V cap, which is in theory cheap, compared to other Nichicon Caps which can be $1.00+ per cap sometimes.

    Would it make sense to use one of these in a power supply?
     
  9. marshallf3

    Well-Known Member

    Jul 26, 2010
    2,358
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    Must not be much special to them, more a marketing move than anything. Compare the spec sheets to see what, if anything is different then choose whichever you like the best.
     
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