摘要： 材料BOM表：R1 = 10K R2 = 22K R3 = 22K R4 = 100K R5 = 56K R6 = 5.6K R7 = 560R R8 = 2.2K R9 = 56K R10 = 56K R11 = 1K R12 = 33K R13 = 330R C1 = 100nF-63V C2 = 10µF-25V C3 = 470µF-25V C4 = 47µF-25V D1 = 5mm. Red LED Q1 = BC327 B1 = 9V PP3 Battery SW1 = 2 poles 4 ways rotary switch IC1 = LM358 Low Power Dual Op-amp MIC1 = Miniature electret microphone (责任编