Parts:

all resistors are 5 or 10 percent tolerance, 1/4-watt

all capacitors are 10 percent tolerance,

rated 35 volts or higher

this circuit amplifies the output of a regular electret condensor microphone quite nicely.. adjust sensitivity by turning R1

Related posts:

1. ecm mic preamp.html
2. balanced microphone preamp
3. alarm control keypad
4. touch activated alarm system
5. 8 Watt amplifier