Now day's audio signal preamp is used in many electronic devices. There are many types of audio preamp circuits from simple to complicated big circuits. Here we are showing you a very good design of a small circuit of signal preamplifier.
circuit is best for providing extra gain to weak audio signals. In this circuit the transistor used is a high gain transistor bc 184, resistor 1 provides the temperature stabilization due to negative feed back and improves frequency response. It also increases impedance to 48K ohms. Transistor Q1 draws 1 milliampere from 9 volt battery.