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 |
|
|
