Condenser Mic Preamplifier Circuit

Last Updated on March 31, 2024

Simple easy to construct Condenser Mic Preamplifier Circuit designed by using sing transistor (BC547). This PreAmplifier circuit constructed to operate with 5V, 500mA DC supply. We know preamplifier is a electronic circuit that converts weak electric Audio Signal from sound transducer to Output Audio signal strong enough for further processing.

Here condenser microphone is a transducer which converts Acoustic sound signal into Electrical Audio Signal. This condenser mic works in the principle of two plate capacitor.

Circuit Diagram

Components Required (BOM)

1	C2, C4, C5	1µF	CP_Radial_D4.0mm_P1.50mm	3
2	C1	22µF	CP_Radial_D4.0mm_P1.50mm	1
3	C3	0.1µF	C_Disc_D3.0mm_W1.6mm_P2.50mm	1
4	R1	4.7KΩ	R_Axial_DIN0204_L3.6mm_D1.6mm_P7.62mm_Horizontal	1
5	R2	1KΩ	R_Axial_DIN0204_L3.6mm_D1.6mm_P7.62mm_Horizontal	1
6	R3	2.2KΩ	R_Axial_DIN0204_L3.6mm_D1.6mm_P7.62mm_Horizontal	1
7	R4	560KΩ	R_Axial_DIN0204_L3.6mm_D1.6mm_P7.62mm_Horizontal	1
8	R5	5.6KΩ	R_Axial_DIN0204_L3.6mm_D1.6mm_P7.62mm_Horizontal	1
9	R6	56Ω	R_Axial_DIN0204_L3.6mm_D1.6mm_P7.62mm_Horizontal	1
10	Q1	BC547	TO-92_Inline	1
11	J1	Conn_01x04_Male	PinHeader_1x04_P2.00mm_Vertical	1

Condenser Mic Not mentioned in Bill of Materials.

Construction & Working

5V DC Supply directly applied to the Condenser mic through R1 Resistor. Output from Mic taken from the positive terminal Capacitor C1, C3 are used as filter capacitors, Electrical Audio signal from mic terminal is applied to the Q1 transistor Base terminal through R2, C4 elements.

Here Q1 transistor configured in common emitter configuration. Output from the transistor taken out from collector terminal followed by C5 capacitor. Audio signal from here can be Amplified by the watts range power amplifier.