If you want to learn about microphone or little use. This is a simple condenser MIC preamp circuit diagram. It changes the sound to electrical signals before sending to a power amplifier. To drive a general speaker.
You can read how condenser microphone works later.
How it works
First of all, we connect a 9V power supply to the circuit. Secondly, a resistor R1 passes an electrical current to biased the Microphone (MIC1). The R1 is a current limiting resistor for MIC1. It is ready to work. When we make a sound to MIC1, it causes the electrical signals to change.
Then, the sound signal flows through a coupling capacitor-C1. Because It will block DC current not pass.
But the signal is very weak. So, it needs helping with a transistor Q1 to increase the signal up.
Next, the signal goes to B of Q1 to amplify more power to out of C—output.
After that, the coupling capacitor C2 pass the AC signal to the output, a tone control preamplifier.
Also, you can connect the output with a headset to convert an electrical signal into sound.
The function of many resistors
- The R1 is a current limiting resistor for MIC1.
- Resistor R2 is biased feedback signal from output to input by connecting between B and C of the transistor Q1. To provide stability for the good work.
- Both R3 and R4 act as to keep a bias voltage level to be suitable.
How to apply it
If you are beginner, here is Connecting a Condenser Microphone Preamp with an amplifier system. Look at below, You should have a tone control preamplifier. Because the output of circuit has lower signal.
This circuit does not have a PCB layout. But you can solder them on the universal PCB Board. Which it may be that difficult for you.
I recommend you Condenser Microphone with Pre-Amp 9VDC Electronic Circuit Kit by Manie Power (Future). I love it.
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