This is a simple Electret Microphone Preamplifier 1 Transistor circuit which can be used between the microphone and stereo amplifier. The microphone amplifier circuit suitable for use with the normal line of amplifier stereo / CD / AUX / Tape inputs. This preamp can take both dynamic and electret microphone inputs. The circuit performance is not superior, but can be used with many projects, not so serious.
The circuit is a simple transistor amplifier with an amplification of about 30-40 dB. The dynamic microphone is just a simple transistor amplifier circuit with nothing special in it. D1 LED on the circuit to show that the circuit works. The voltage drop caused by LED (about 1.8 V for the red LED) is Taten into account when designing the amplifier circuit built around Q1. Resistor R4 and capacitor C5 to a filter to filter out the noise as possible to the battery or power source that is used to power this circuit. Capacitors C1, C2 and C3 are used to block the polarization at the base of Q1 to leave the microphone to microphone
