1 1 2 2 3 3 4 4 D D C C B B A A Title Number RevisionSize A4 Date: 2012/7/29 Sheet of File: β β.SchDoc Drawn By: 8 1 4 3 2 1 U1A NE5532P 8 1 4 3 2 1 U3A NE5532P VCC VCC 8 1 4 3 2 1 U2A NE5532P VCC VSS VSS VSS R11 1k R12 33k R2 1k R3 33k R5 10k R8 10k R7 10k GND 1 2 3 4 P2 Header 4 C3 10uf C 3 B2 E 1 Q2 2N2222 R1 1k R13 1k R9 600 VCC VSS D1 Diode R4 820 D2 Diode R10 820 C5 0.1U C4 10U GNDGND C1