* SPICE netlist
XU1 0 N005 Vcc 0 N006 uA741 ;pnba In+)In-)V+)V-)OUT
XU2 0 N002 Vcc 0 N003 uA741 ;pnba In+)In-)V+)V-)OUT
XU3 0 N004 Vcc 0 N001 uA741 ;pnba In+)In-)V+)V-)OUT
XU4 0 N007 Vcc 0 N008 uA741 ;pnba In+)In-)V+)V-)OUT
R6 N004 N008 {R}
R1 N005 N003 {R}
R2 N002 N001 {R}
R3 N004 N001 {R}
R4 N008 N007 {R}
R5 N004 N006 {R}
C1 N006 N005 {C}
C2 N003 N002 {C}
C3 N001 N004 {C}
D1 N003 N007 D
V1 Vcc 0 15
.inc uA741.lib
.tran 10
.param R=10K
.param C=10n

* LTspice schematic (.asc)
Version 4
SHEET 1 1264 832
WIRE -40 -416 -552 -416
WIRE 488 -352 440 -352
WIRE -344 -336 -392 -336
WIRE -136 -336 -280 -336
WIRE 440 -320 440 -352
WIRE -216 -256 -216 -288
WIRE -552 -240 -552 -416
WIRE -504 -240 -552 -240
WIRE -392 -240 -392 -336
WIRE -392 -240 -424 -240
WIRE -248 -240 -392 -240
WIRE -136 -224 -136 -336
WIRE -136 -224 -184 -224
WIRE -88 -224 -136 -224
WIRE -40 -224 -40 -416
WIRE 280 -224 -40 -224
WIRE -248 -208 -296 -208
WIRE 504 -208 424 -208
WIRE 424 -176 424 -208
WIRE -296 -160 -296 -208
WIRE -216 -144 -216 -192
WIRE 88 -144 56 -144
WIRE 280 -144 280 -224
WIRE 280 -144 152 -144
WIRE -88 -80 -88 -224
WIRE -88 -80 -632 -80
WIRE 200 -80 200 -112
WIRE -40 -64 -40 -224
WIRE 56 -64 56 -144
WIRE 56 -64 40 -64
WIRE 104 -64 56 -64
WIRE 168 -64 104 -64
WIRE 424 -64 424 -96
WIRE 280 -48 280 -144
WIRE 280 -48 232 -48
WIRE 168 -32 136 -32
WIRE -456 0 -488 0
WIRE -280 0 -392 0
WIRE 136 0 136 -32
WIRE 200 32 200 -16
WIRE -360 64 -360 32
WIRE -632 80 -632 -80
WIRE -584 80 -632 80
WIRE -488 80 -488 0
WIRE -488 80 -504 80
WIRE -392 80 -488 80
WIRE -280 96 -280 0
WIRE -280 96 -328 96
WIRE -216 96 -280 96
WIRE 104 96 104 -64
WIRE 104 96 -136 96
WIRE 632 96 104 96
WIRE -392 112 -440 112
WIRE -440 160 -440 112
WIRE -360 176 -360 128
WIRE 280 192 232 192
WIRE 408 192 360 192
WIRE 312 288 312 256
WIRE -632 304 -632 80
WIRE 104 304 -632 304
WIRE 232 304 232 192
WIRE 232 304 168 304
WIRE 280 304 232 304
WIRE 408 320 408 192
WIRE 408 320 344 320
WIRE 488 320 408 320
WIRE 632 320 632 96
WIRE 632 320 568 320
WIRE 280 336 248 336
WIRE 248 368 248 336
WIRE 312 416 312 352
FLAG -440 160 0
FLAG -296 -160 0
FLAG 136 0 0
FLAG 248 368 0
FLAG 440 -320 0
FLAG 488 -352 VEE
FLAG 200 32 VEE
FLAG -216 -144 VEE
FLAG -360 176 VEE
FLAG 312 416 VEE
FLAG 424 -64 0
FLAG 504 -208 Vcc
FLAG 200 -112 Vcc
FLAG -216 -288 Vcc
FLAG -360 32 Vcc
FLAG 312 256 Vcc
SYMBOL OpAmps\\opamp2 -360 32 R0
SYMATTR InstName U1
SYMATTR Value uA741
SYMBOL OpAmps\\opamp2 -216 -288 R0
SYMATTR InstName U2
SYMATTR Value uA741
SYMBOL OpAmps\\opamp2 200 -112 R0
SYMATTR InstName U3
SYMATTR Value uA741
SYMBOL OpAmps\\opamp2 312 256 R0
SYMATTR InstName U4
SYMATTR Value uA741
SYMBOL res 584 304 R90
SYMATTR InstName R6
SYMATTR Value {R}
SYMBOL res -488 64 R90
SYMATTR InstName R1
SYMATTR Value {R}
SYMBOL res -408 -256 R90
SYMATTR InstName R2
SYMATTR Value {R}
SYMBOL res 56 -80 R90
SYMATTR InstName R3
SYMATTR Value {R}
SYMBOL res 376 176 R90
SYMATTR InstName R4
SYMATTR Value {R}
SYMBOL res -120 80 R90
SYMATTR InstName R5
SYMATTR Value {R}
SYMBOL cap -392 -16 R90
SYMATTR InstName C1
SYMATTR Value {C}
SYMBOL cap -280 -352 R90
SYMATTR InstName C2
SYMATTR Value {C}
SYMBOL cap 152 -160 R90
SYMATTR InstName C3
SYMATTR Value {C}
SYMBOL diode 104 320 R270
SYMATTR InstName D1
SYMBOL voltage 424 -192 R0
SYMATTR InstName V1
SYMATTR Value 15