Low impedance microphone amplifier

Description

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.

 

Schematic diagram

 

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