This is single chip dynamic microphone preamplifier which is design to drive using commonly available 12V single rail power supplies. Preamplifier in this article is build around popular NE5532 dual low noise operational amplifier IC and this preamplifier is specifically constructed to drive professional 600Ω dynamic microphones.

This preamplifier consists with two amplifier stages and initial amplifier is design to get 36dB gain and final preamplifier is used to get 16dB of gain.
Preamplifier gain controller is placed in between those two amplifiers and this separation allows reducing clipping in output waveform.

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Gain control assembly with 4.7KΩ resistor and 4.7μF capacitor.

In prototyping stages we test this preamplifier with few 600Ω dynamic microphones with TDA2050 power amplifier. According to our observations this unit produces excellent output with all of these microphones. To get professional results use this preamplifier with 12V battery or with regulated power supply unit and use screened wires for both input and output connections.

Finished dynamic microphone preamplifier prototype.
Finished dynamic microphone preamplifier prototype.

Project Related Downloads


Schematic, wiring diagrams and PCB design of Dynamic microphone preamplifier.

References


NE5532 - Dual Low-Noise Operational Amplifier
Microphone Database