低阻抗麦克风放大器电路 (Low impedance microphone amplifier) The circuit is a microphone amplifier for use with low impedance (~200 ohm) microphones. It will work with stabilized voltages between 6-30VDC. If you don't build the impedance adapter part with T1, you get a micamp for higher impedance microphones. In this case, you should directly connect the signal to C7. 
Layout of board 
printed PCB 
Parts R1=15k C1= 3k9 U1= TL081 R2= 150k C2= 100u D1= 1N4148 R3= 2k2 C3= 22u CN1= SIL6 R4= 820 C4= 4u7 R6= 10k C5= 470u R7= 10k C6= 10u P1= 1M C7= 100n C8= 47u UNIPOLAR |