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 9-30VDC. 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
Components
|
Name |
Value |
|
R1 |
15k |
|
R2 |
150k |
|
R3 |
2k2 |
|
R4 |
820 |
|
R5 |
680 |
|
R6 |
10k |
|
R7 |
10k |
|
P1 |
1M |
|
|
Name |
Value |
|
C1 |
3k9 |
|
C2 |
100u |
|
C3 |
22u |
|
C4 |
4u7 |
|
C5 |
470u |
|
C6 |
10u |
|
C7 |
100n |
|
C8 |
47u UNIPOLAR |
|
|
Name |
Value |
|
U1 |
TL081 |
|
D1 |
1N4148 |
|
T1 |
BC109 |
|
CN1 |
SIL6 |
|
|
