Dynamic and Electret Condenser Microphone Preamp Circuit

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Introduction

A microphone preamplifier, often known as a mic preamp, is a device that amplifies the microphone’s signal to raise its level. Preamplifiers for microphones have two major functions: first, they set the appropriate load impedance for the output of the microphone, and second, they receive the incoming signal from the mic and amplify it to an acceptable level. Typically, the signal emanating straight from a microphone is relatively quiet. By adding the proper voltage gain as quickly as possible, a preamp makes the signal usable. To understand this, in this Tutorial, we are going to make a “Simple dynamic and electret condenser microphone preamp circuit”.

The majority of microphone preamps’ main goal is to provide gain to the signal without affecting the sound of the signal. This is challenging to do in practice since most amplifiers introduce some noise and distortion into the signal. Thus, in this circuit to improve the circuit’s response to the signal, two transistors are directly coupled together.

Hardware Required

S.no	Component	Value	Qty
1.	LED & Switch	–	1,1
2.	Resistor	1k,4.7K,220K,100 ohm	1,1,1,1
3.	Capacitor	10uf,100uf	4,1
4.	Dynamic & Electret MIC	–	1,1
5.	Transistor	C9013	1

Circuit Diagram

Working Explanation

We are utilizing Q1 and Q2 as the two transistors in this Simple dynamic and electret condenser microphone preamp circuit. The emitter of Q1 will get a feedback signal from the Q2 collector. In that way, It has better frequency responsiveness. Additionally, R1 transmits voltage from Q2’s emitter to bias Q1. Q1 and Q2 amplify the input signal coming from capacitor C1 for the amplifier. The output signal from Q2’s collector is then transmitted through capacitor C6 and into a power amplifier.

We employ a simple circuit for the power supply, including the full wave rectifier, diodes D1, D2, and filter capacitorC7, as illustrated here: