Designed this little module to add a line out to a RF lav mic belt pack I picked up cheap on eBay.Built with the parts list provided it has a gain factor of 51 (appx. 10mV in, 500mV out) with a noise level more than sufficient for audio applications. Runs off a single ended DC power supply from 2.7 to 5V, and can easily be adapted to other small signal amplification tasks in the audio frequency range by changing the biasing and feedback resistors.