This electret microphone amplifier is designed using common electronic components. This microphone amplifier uses an electret microphone capsule, but can be an dynamic microphone, 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 circuit has
a very low power consumption (about 1. 5m), circuit can be powered using a 9 volt battery. The values for R1, C3 and R8 are for Philips LBC1055/00 electret capsule.