Apr 18, 2018 · These are many simple audio amplifier circuit diagram using transistor. Currently, ICs has been used in many audio amplifiers, especially small circuit. It is convenient to use transistors.But when you need to use transistors, it has several advantages, such as saving you can take old equipment come to made small circuits easier than the IC. Schematic of very Simple preamplifiers using 2N3904. In electronics, a common emitter amplifier is used as a voltage amplifier. In this circuit the base terminal of the transistor serves as the input, the collector is the output, and the emitter is common.

2N3904 General Purpose Transistors NPN TO-92 Page 1 12/05/08 V1.1 High Speed Switching Features: • NPN silicon planar switching transistors. • Fast switching devices exhibiting short turn-off and low saturation voltage characteristics.