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.
Printed Circuit Board
Condenser Mic Preamplifier Circuit Gerber Files.
Interactive Board Viewer
Hello,does this circuit work will all microphones of that type? if not what would change and why?
This Pre Amplifier circuit designed to work with All types of Condenser Microphone. This Circuit may require some specification changes according to the input impedance of Amplifier.
This Circuit is a great design, works great on a 200R impedance mic, i use it for pre amplifying on my analogue to digital conversion. So far with experimenting works excellent. Low noise pickup great response gain not to high to pick up movement noise.
I tried this design in protus but unfortunately, it doesn’t work…
Why?