Need help with biasing a common emitter amplifier

Discussion in 'The Projects Forum' started by EarlAnderson, Jun 1, 2012.

  1. EarlAnderson

    Thread Starter Member

    Nov 13, 2011
    166
    4
    I am trying to build a common emitter amplifier as a preamp stage to a class AB output amplifier which I plan to use to drive a couple of speakers, but I'm having a little trouble trying to figure out the right resistor values to use to bias it. I've turned to the Internet for help, with no luck so far. It would be much appreciated if someone could help me with choosing the right resistor values to use. Thanks :)
     
  2. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
    363
  3. #12

    Expert

    Nov 30, 2010
    16,298
    6,811
    Would you settle for a low noise jfet preamp?
     
  4. EarlAnderson

    Thread Starter Member

    Nov 13, 2011
    166
    4
    I would use that but I don't have any spare jfets lying around so I was thinking about using a 2N3904
     
  5. #12

    Expert

    Nov 30, 2010
    16,298
    6,811
    If you run into noise problems, the jfet is good at fixing that.
    It all depends on exactly what levels of signal you are trying to pre-amp.
    Good calculating.
     
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