Microphone Amplifier Circuit for 4-ohm 3W Speaker

Discussion in 'The Projects Forum' started by raisintoe, Oct 4, 2016.

  1. raisintoe

    Thread Starter Member

    Mar 24, 2012
    46
    0
    Hey, I am trying to design a simple Audio amplifier with components that I have on hand. The only limitation I think I have is my choice of op-amps, I only have basic op-amps, but they have a quick response time.

    This is the circuit I have come up with so far. I am not sure how to make it more realistic for the 4-ohm resistor on the right. It is dissipating way too much power. any suggestions will help, this is new to me.

    MicAmp.png
     
  2. #12

    Expert

    Nov 30, 2010
    16,302
    6,812
    What you have here is a Class A amplifier and you just found out why they have an efficiency of less than 50%. The best way to beat this is to use a push-pull design. Vacuum tube amplifiers used a transformer to convert high voltage/low current to low voltage/high current but there is no point in that with a transistor design.
     
    raisintoe likes this.
  3. AlbertHall

    Well-Known Member

    Jun 4, 2014
    1,951
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    raisintoe likes this.
  4. raisintoe

    Thread Starter Member

    Mar 24, 2012
    46
    0
    Thank you guys, I built one of those audio amplifiers from that link you sent me Albert; it works well!
     
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