Electret microphone amplifier circuit schematic

A simple microphone amplifier can be achieved using electronic scheme below. This amplifier uses a microphone to electret microphone capsule, but can be used can be used and dynamic microphones, which have a low resistance. This circuit requires a supply voltage between 5 and 10 volts, is recommended to use a supply voltage of 9 volts DC . Since the assembly has a very low power consumption (about 1.5m), installation can be powered using a 9 volt battery. The values for R1, C3 and R8 are for Philips LBC1055/00 electret capsule.
Amplification depends on the ratio R7/R3, is greater than 100.

Circuit Diagram: