How to design audio amplifier with op amp and filters

Discussion in 'Homework Help' started by kungfupanda1947, Dec 2, 2009.

  1. kungfupanda1947

    Thread Starter New Member

    Dec 2, 2009
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    Use op amp and filter circuits to build an audio amplifier from 20 to 20k Hz with a gain of 20 (or -20). Check points: 1) -3dB frequencies at 20 Hz and 20k Hz. 2) voltage gain of 20 in mid-band.

    Please draw the circuit diagram with calculated values and equations
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    What progress have you made, so far? Can you post your work/schematics?
     
  3. kungfupanda1947

    Thread Starter New Member

    Dec 2, 2009
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    0
    thanx for replying, honestly i have very little idea of how to do this but as of now i can just think of cascading a high pass and low pass to make a band pass and then cascading it to a op amp (uA741). I know the equations to calculate all values but could you tell me whether the start is a correct way or not please.
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    It is more conventional in audio amps to use the input R - C characteristic to set the lower response, and to let the feedback network to roll off response at the top. That is not the only way, but it is one of them.

    Can you use something more modern than a 741? That design is 40 years old. Modern op amps are vastly superior.

    When you say audio amplifier, do you mean something to drive a loudspeaker, or just an amp with a passband characteristic?
     
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