The values from the schematic correspond to 1000x amplification. Noise signal ratio is 95dB. Distorsions were 0.006% at 1kHz and 0dBV and lower than 0.01% at 10kHz. Bandwidth is 180kHz at 3V and 1kΩ ...

This dynamic microphone amplifier circuit has a total gain of 200 times. If we use 200Ω microphones R4 must be 220Ω and C1 is 4.7uF. If you want the to. ... Dynamic microphone amplifier circuit ...