“A small microphone amplifier circuit using operational amplifier in single power supply mode.
Thinking a little bit on audio recording device, Mic section attracted my attention. In mobiles inbuilt amplifier is enough to record the sound via external microphone. That’s why no preamplifier required. But while recording with camera device this mic system is not provide enough gain and hence voice get distorted. So, we always use a microphone which has camera option. This usually increase the signal gain.
Components required:
1) JRC4558D operational amplifier
2) Condenser microphone
3) 1M, 100K, 10K and 2k2 resistor
4) 1nf and 1uf ceramic capacitors
5) 5-volt power supply
6) Custom PCB files”