The preamplifier circuit is a circuit that extends the signal from the source sound to signal the strength to go into a power amplifier circuit to trigger the required sector preamplifier is also due to signal from the source voice Some levels. sounds very light, such as tape or tuner, some will have strength of signals in the heart uV is required to use the preamplifier circuit expanded signal strength to strength in the area mV to access the power amplifier for amplifier efficiency.
By entering into power supply 9volt circuit Q1 and Q2 to a direct coupling circuit to transmit better. When the signal input through the C1 coupling into the signal to Q1.
Amplifier to a level of C to stand out in Q2 into the amplifier once again to provide better stability. Then signal to leave the output pin C of Q2 through C6 coupling signal from output and the output signal a part of Q2 will feed black feedback through to the C4, C3 and R3 comes to the pin E in Q1 in order to help the range of frequency response.
With superior audio output that can be connected to the amplifier region.