This circuit be signal sound expansion from condenser microphone give with small-sized loudspeaker. It compose the importance is part pre mic use transistor just one enlarge sound signal gives the power goes up change come to a part amplifier with the integrated circuit LM386 utter go out give a loudspeaker.
When feed 9V power supply reach the circuit. The MIC1 and Q1 which be part pre mic, by mic will take sound signal has come in then deliver Q1 enlarge a signal has power size goes up to go out the way collector pin (C) change C2 coupling signal. Then deliver with VR1 for fine signal sound level gives with Input of IC1. Which IC1 number LM386 be the integrated circuit amplifies 1 watt size has pin 3 are input and have C3 will eradicate source noise with input signal discharge down ground. When amplify finished will export come to the way output pin 5 by have C5 and R5 eradicate a signal takes to stir go out sound signal will have that to change go to still. The C6 coupling signal and enhance sound quality of low frequency improve. Before reach a loudspeaker makes a noise to come out.
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