From Microphone to Line Input: Design Tips

The requirements a microphone pre-amplifier is expected to meet are very different from those formulated for a line amplifier. For the first, a large gain and a low noise contribution are very important, while a line amplifier has to be able to handle a much larger signal without generating distortion. A microphone input has a sensitivity of a few millivolts; a line input must be able to cope with several volts.