Low noise Mini Electret Microphone PreAmplifier
The single supply microphone pre-amplifier amplifies the output signal of an electret capsule microphone to audio line levels. An op amp is used as a trans-impedance amplifier to convert the output current from the microphone in to a signal level voltage.
The single supply microphone pre-amplifier amplifies the output signal of an electret capsule microphone to audio line levels. An op amp is used as a trans-impedance amplifier to convert the output current from the microphone in to a signal level voltage. The circuit works with 9V so it is good choice for battery operated systems.
Features
- Supply 9V DC
- Current Approx. 3mA
- On Board Microphone
- Very thin and narrow PCB
Low noise Mini Electret Microphone PreAmplifier – [Link]
The schematic shows the polarity of the output capacitor is connected backwards. A polarized capacitor is used at the input but its polarity is unknown, an unpolarised film capacitor should be used.