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.


  1. K.Mounika

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

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

  3. virendra kalam

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

  4. seetharaman

    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).

  5. 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?

  6. its a simple one for learning students to start with.

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

  8. rk mishra

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