Small Surround Sound Decoder
Based on four chips, TL072, TL074, MN3101, and MN3004 which produce four channels of output, the center, rear, front right, and front left surround audio accommodated in a signal of left and right channels. The circuit however can be applied with other basic functions as a standard decoder.
The input operational of amplifier driven by IC TL072. The outputs on these operational amplifiers would serve as the input buffer to TL074. MN3004 work as oscillator and op-amp that triggered by output of MN3101, a CMOS large scale integration generating two phase clock signal of low output impedance used as Bucket Brigade Delay (BBD) clock generator/driver.
Circuit Parts
R1,R2,R7,R8,R12,R13,R18,R19,R20___________47K
R3,R4,R5,R6,R21,R22,R34,R35_______________10K
R9,R10,R11,R14,R15,R16,R17________________15K
R23,R24,R25,R33,R36_______________________100
R26,R27,R28,R31,R32_______________________100K
R29,R30___________________________________5K6
RV1,RV2___________________________________2X10K Log pot
RV3,RV4___________________________________10K Log pot
C1,C8_____________________________________47uF/25V
C2,C7,C9,C14,C23__________________________47nF/100V
C3,C6_____________________________________1uF/100V
C4,C5,C10_________________________________33pF/100V
C11,C12,C15_______________________________10uF/25V
C13_______________________________________82nF
C16_______________________________________18pF/100V
C17_______________________________________100pF mini adjustable capacitor
C18_______________________________________2.2nF
C19_______________________________________4.7uF/25V
C20_______________________________________100nF/100V
C21_______________________________________10nF
C22_______________________________________180pF
C24_______________________________________150nF
D1________________________________________1N4148
IC1,IC6___________________________________TL072
IC2,IC3___________________________________TL074
IC4_______________________________________MN3101
IC5_______________________________________MN3004
JI-J6_____________________________________RCA female jack
[source:Circuit-Project]