Low Impedance Microphone Amplifier Circuit

This circuit is a microphone amplifier that has low impedance. Usually, a microphone with low impedance is in a dynamic microphone. This microphone amplifier circuit can work well at 6 VDC voltage up to 30 VDC. The required voltage range in this circuit will allow you to design the amplifier as desired.

If you build a circuit without using a T1 transistor, then the input of this mic amplifier is high impedance. If this is done you should connect the mic with capacitor C7.

Potentiometer P1 functions as a feedback setting of IC Op-Amp. This will affect the output gain. In order for this circuit to work optimally, then the power supply used must be well regulated. Even if not possible, this microphone amplifier circuit can operate with the battery.

Schematic diagram

low impedance microphone amplifier circuit
Image by www.electronics-lab.com

Parts list of low impedance microphone amplifier circuit

  • R1=15k
  • R2= 150k
  • R3= 2k2
  • R4= 820
  • R6= 10k
  • R7= 10k
  • P1= 1M
  • C1= 3k9
  • C2= 100u
  • C3= 22u
  • C4= 4u7
  • C5= 470u
  • C6= 10u
  • C7= 100n
  • C8= 47u UNIPOLAR
  • D1= 1N4148
  • U1= TL081
  • CN1= SIL6

Layout of boardlow impedance microphone amplifier pcb top

Printed PCB

low impedance microphone amplifier pcb bottom