Hello Audio GuruA microphone mounted on your chest picks up weak direct voice sounds but also picks up echoes in the room.
Use a gooseneck mic a few cm away from your mouth instead for clear and loud speach.
The Velleman kit is for a hand-held dynamic mic (coil and magnet), not for a modern electret mic. It does not power an electret mic.
The kit uses a lousy old LM358 opamp that has hiss, crossover distortion and a poor high frequency response.
The gain is probably too low for what you need.
You can plugin a modern audio opamp instead (OPA2134) and change one resistor to increase the gain.
Ah, sorry about that.Hello,
@ebeowulf17 , The kit is not suitable for an electret microphone.
There is no bias for an electret microphone in the schematic:
View attachment 181994
It is likely to be used with a dynamic microphone.
To make it suitable for an electret microphone, remove R1 (100K) and connect a resistor of 10K to the powersupply.
thank very much sirYou do not want to feed the 10k resistor that powers the mic directly from the raw and dirty power supply voltage, instead add a 1k resistor to the power supply voltage then connect the 10k resistor to it. Then add a 47uF filter capacitor to ground at where the two resistors are joined.
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