Signal tracer circuit.

admin April 7, 2010 13 Comments


A high gain amplifier circuit that can be operated from a battery pack of 6 or 9 volt battery pack is shown here.The IC1 uA 741 is wired as a high gain non-inverting amplifier and its output is amplified by a pair of complementary transistors (Q1 & Q2) to drive the speaker.The negative feedback from the common emitter junction of the two transistor stabilizes the gain of the circuit.The resulting audio output is sufficient to serve as a signal tracer.

Circuit diagram with Parts list.



  • Assemble the circuit on a  good quality PCB or  common board .
  • The POT R6 can be used as a volume controller.
  • The circuit can be powered from a 6 or 9V DC battery pack.
  • The IC1 must be mounted an an IC base.
  • All capacitors must be rated at least 15V.
  • March 16, 2013

    This site very useful every tech. student .And it is easy to understandable.

  • aakash
    April 21, 2012

    I want the whole pdf of this signal tracer with more applications in it ,could u please send me

  • February 23, 2011

    Hi sir,
    i want complete pdf file of this project.could you please send me.

  • seetharaman
    July 23, 2010

    Hi George
    3 ohms is too low an impedance for this amp. try with 8 ohms it will be ok. or with 2nos 8 ohms speaker in series it will be still better. ensure output transistors are the recommended germanium matched pair only(this pair requires very low standing current to avoid crossover distortion).

  • george
    July 22, 2010

    I built the circuit from the picture, and there is one issue to deal with: when I put 60 Ohm headphones, everything sounds good. But when I put 3 Ohm loudspeaker, the distortion is heard from it. I know this is not the right place to ask such question, but what should I do to solve this issue?

  • kometa
    July 14, 2010

    its a simple one for learning students to start with.

  • M.AbuBakar
    May 12, 2010

    awesome……Its working…………

  • harish
    February 5, 2010

    wht s d main use of dis circuit………
    i need complete information

  • laxman
    August 5, 2009

    its really helpful to the students….

  • rk mishra
    April 5, 2009

    this is rk mishra here..I see this project and obseerve that this is the best from other.

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