* SPICE netlist
R12 0 N012 1k
R13 N012 N001 1k
R14 N001 N007 22k
R15 N014 N002 500
R16 N002 N003 2k
R17 N003 N013 10k
R18 N008 N004 1k
R19 N004 N016 4.7k
C5 N006 N012 4.7n
C6 N001 N007 100p
C7 N007 N014 1.5n
C8 N013 0 270p
V5 N011 N010 SINE(0 10m 50k)
V6 a 0 9
V7 0 b 9
R21 N009 N005 1k
XU7 0 N009 a b N006 LT1057 ;pnba In+)In-)V+)V-)OUT
XU8 0 N001 a b N007 LT1057 ;pnba In+)In-)V+)V-)OUT
XU9 N015 N002 a b N003 LT1057 ;pnba In+)In-)V+)V-)OUT
XU10 0 N004 a b N016 LT1057 ;pnba In+)In-)V+)V-)OUT
XU11 N011 N005 a b N005 LT1057 ;pnba In+)In-)V+)V-)OUT
XU12 N013 N008 a b N008 LT1057 ;pnba In+)In-)V+)V-)OUT
V8 N010 0 SINE(0 2m 11k)
R22 N015 0 2.2k
R37 N028 N017 1k
R38 N017 N023 22k
R39 N030 N018 500
R40 N018 N019 2.2k
R41 N019 N029 11k
R42 N024 N020 1k
R43 N020 N032 4k
C18 N017 N023 100p
C19 N023 N030 1.8n
C20 N029 0 220p
V9 N027 N026 SINE(0 6m 50k)
R44 N028 N022 10k
R45 N022 N025 1k
XU19 0 N022 a b N028 LT1057 ;pnba In+)In-)V+)V-)OUT
XU20 0 N017 a b N023 LT1057 ;pnba In+)In-)V+)V-)OUT
XU21 N031 N018 a b N019 LT1057 ;pnba In+)In-)V+)V-)OUT
XU22 0 N020 a b N032 LT1057 ;pnba In+)In-)V+)V-)OUT
XU23 N027 N021 a b N021 LT1057 ;pnba In+)In-)V+)V-)OUT
XU24 N029 N024 a b N024 LT1057 ;pnba In+)In-)V+)V-)OUT
V12 N026 0 SINE(0 2m 10k)
R46 N031 0 2.2k
R31 0 N025 50
C17 N025 N021 100n
D1 N016 P001 D
C21 P001 0 4.7n
C22 P002 0 1n
D2 N032 P002 D
R1 N006 N009 10k
.tran 10ms

* LTspice schematic (.asc)
Version 4
SHEET 1 1952 768
WIRE -80 -384 -96 -384
WIRE 240 -336 208 -336
WIRE 352 -336 320 -336
WIRE 768 -336 736 -336
WIRE -608 -320 -784 -320
WIRE -336 -320 -432 -320
WIRE -96 -320 -96 -384
WIRE -80 -320 -96 -320
WIRE 0 -320 0 -384
WIRE 0 -320 -16 -320
WIRE 640 -288 512 -288
WIRE -784 -256 -784 -320
WIRE -720 -256 -784 -256
WIRE -608 -240 -608 -320
WIRE -608 -240 -656 -240
WIRE -512 -240 -512 -320
WIRE -512 -240 -528 -240
WIRE -416 -240 -512 -240
WIRE -96 -240 -96 -320
WIRE -96 -240 -112 -240
WIRE -80 -240 -96 -240
WIRE 208 -240 208 -336
WIRE 208 -240 192 -240
WIRE 256 -240 208 -240
WIRE 512 -240 512 -288
WIRE 560 -240 512 -240
WIRE -896 -224 -976 -224
WIRE -720 -224 -848 -224
WIRE -336 -224 -336 -320
WIRE -336 -224 -352 -224
WIRE -320 -224 -336 -224
WIRE -224 -224 -256 -224
WIRE -192 -224 -224 -224
WIRE -112 -224 -112 -240
WIRE 0 -224 0 -320
WIRE 0 -224 -16 -224
WIRE 352 -224 352 -336
WIRE 352 -224 320 -224
WIRE 384 -224 352 -224
WIRE 480 -224 464 -224
WIRE 512 -224 480 -224
WIRE 640 -224 640 -288
WIRE 640 -224 624 -224
WIRE 656 -224 640 -224
WIRE 736 -224 736 -336
WIRE 752 -224 736 -224
WIRE -416 -208 -448 -208
WIRE -80 -208 -96 -208
WIRE 0 -208 0 -224
WIRE 32 -208 0 -208
WIRE 112 -208 96 -208
WIRE 192 -208 192 -240
WIRE 256 -208 240 -208
WIRE 512 -208 512 -224
WIRE 560 -208 512 -208
WIRE 848 -208 848 -336
WIRE 848 -208 816 -208
WIRE -448 -192 -448 -208
WIRE 240 -192 240 -208
WIRE 752 -192 736 -192
WIRE 480 -176 480 -224
WIRE -224 -160 -224 -224
WIRE -96 -160 -96 -208
WIRE 736 -160 736 -192
WIRE -896 -112 -896 -224
WIRE -848 -112 -848 -144
WIRE -848 -112 -896 -112
WIRE -976 -96 -976 -144
WIRE -848 -80 -848 -112
WIRE -64 80 -80 80
WIRE 256 128 224 128
WIRE 368 128 336 128
WIRE 784 128 752 128
WIRE -624 144 -768 144
WIRE -592 144 -624 144
WIRE -336 144 -432 144
WIRE -80 144 -80 80
WIRE -64 144 -80 144
WIRE 16 144 16 80
WIRE 16 144 0 144
WIRE 656 176 528 176
WIRE -768 208 -768 144
WIRE -704 208 -768 208
WIRE -624 224 -624 144
WIRE -624 224 -640 224
WIRE -528 224 -560 224
WIRE -432 224 -432 144
WIRE -432 224 -448 224
WIRE -336 224 -432 224
WIRE -80 224 -80 144
WIRE -80 224 -96 224
WIRE -64 224 -80 224
WIRE 224 224 224 128
WIRE 224 224 208 224
WIRE 272 224 224 224
WIRE 528 224 528 176
WIRE 576 224 528 224
WIRE -880 240 -960 240
WIRE -704 240 -832 240
WIRE -256 240 -256 144
WIRE -256 240 -272 240
WIRE -176 240 -256 240
WIRE -96 240 -96 224
WIRE 16 240 16 144
WIRE 16 240 0 240
WIRE 368 240 368 128
WIRE 368 240 336 240
WIRE 400 240 368 240
WIRE 496 240 480 240
WIRE 528 240 496 240
WIRE 656 240 656 176
WIRE 656 240 640 240
WIRE 672 240 656 240
WIRE 752 240 752 128
WIRE 768 240 752 240
WIRE -336 256 -368 256
WIRE -64 256 -80 256
WIRE 16 256 16 240
WIRE 48 256 16 256
WIRE 128 256 112 256
WIRE 208 256 208 224
WIRE 272 256 256 256
WIRE 528 256 528 240
WIRE 576 256 528 256
WIRE 864 256 864 128
WIRE 864 256 832 256
WIRE 912 256 864 256
WIRE -368 272 -368 256
WIRE 256 272 256 256
WIRE 768 272 752 272
WIRE -560 288 -560 224
WIRE 496 288 496 240
WIRE -80 304 -80 256
WIRE 752 304 752 272
WIRE -880 352 -880 240
WIRE -832 352 -832 320
WIRE -832 352 -880 352
WIRE -960 368 -960 320
WIRE -832 384 -832 352
FLAG -224 -80 0
FLAG 736 -160 0
FLAG 480 -112 0
FLAG -96 -160 0
FLAG -480 0 0
FLAG -320 -48 0
FLAG -480 -80 a
FLAG -48 -256 a
FLAG -384 -256 a
FLAG 288 -256 a
FLAG 784 -240 a
FLAG -320 32 b
FLAG -384 -192 b
FLAG -48 -192 b
FLAG 288 -192 b
FLAG 784 -176 b
FLAG -448 -192 0
FLAG -688 -272 a
FLAG -688 -208 b
FLAG 592 -256 a
FLAG 592 -192 b
FLAG -976 -96 0
FLAG 240 -112 0
FLAG 752 304 0
FLAG 496 352 0
FLAG -80 304 0
FLAG -32 208 a
FLAG -304 208 a
FLAG 304 208 a
FLAG 800 224 a
FLAG -304 272 b
FLAG -32 272 b
FLAG 304 272 b
FLAG 800 288 b
FLAG -368 272 0
FLAG -672 192 a
FLAG -672 256 b
FLAG 608 208 a
FLAG 608 272 b
FLAG -960 368 0
FLAG 256 352 0
FLAG -560 368 0
FLAG 912 -144 0
FLAG 976 320 0
SYMBOL Res -208 -64 R180
SYMATTR InstName R12
SYMATTR Value 1k
SYMBOL Res -208 -208 R270
SYMATTR InstName R13
SYMATTR Value 1k
SYMBOL Res -96 -368 R270
SYMATTR InstName R14
SYMATTR Value 22k
SYMBOL Res 96 -192 R270
SYMATTR InstName R15
SYMATTR Value 500
SYMBOL Res 224 -320 R270
SYMATTR InstName R16
SYMATTR Value 2k
SYMBOL Res 368 -208 R270
SYMATTR InstName R17
SYMATTR Value 10k
SYMBOL Res 640 -208 R270
SYMATTR InstName R18
SYMATTR Value 1k
SYMBOL Res 752 -320 R270
SYMATTR InstName R19
SYMATTR Value 4.7k
SYMBOL Cap -320 -208 R270
SYMATTR InstName C5
SYMATTR Value 4.7n
SYMBOL Cap -80 -304 R270
SYMATTR InstName C6
SYMATTR Value 100p
SYMBOL Cap 32 -192 R270
SYMATTR InstName C7
SYMATTR Value 1.5n
SYMBOL Cap 464 -176 R0
SYMATTR InstName C8
SYMATTR Value 270p
SYMBOL Voltage -848 -240 R0
SYMATTR Value SINE(0 10m 50k)
SYMATTR InstName V5
SYMBOL Voltage -480 -96 R0
SYMATTR InstName V6
SYMATTR Value 9
SYMBOL Voltage -320 -64 R0
SYMATTR InstName V7
SYMATTR Value 9
SYMBOL Res -512 -256 R90
SYMATTR InstName R21
SYMATTR Value 1k
SYMBOL OpAmps/LT1057 -384 -288 R0
SYMATTR InstName U7
SYMBOL OpAmps/LT1057 -48 -288 R0
SYMATTR InstName U8
SYMBOL OpAmps/LT1057 288 -288 R0
SYMATTR InstName U9
SYMBOL OpAmps/LT1057 784 -272 R0
SYMATTR InstName U10
SYMBOL OpAmps/LT1057 -688 -304 R0
SYMATTR InstName U11
SYMBOL OpAmps/LT1057 592 -288 R0
SYMATTR InstName U12
SYMBOL Voltage -976 -240 R0
SYMATTR Value SINE(0 2m 11k)
SYMATTR InstName V8
SYMBOL Res 224 -208 R0
SYMATTR InstName R22
SYMATTR Value 2.2k
SYMBOL Res -192 256 R270
SYMATTR InstName R37
SYMATTR Value 1k
SYMBOL Res -80 96 R270
SYMATTR InstName R38
SYMATTR Value 22k
SYMBOL Res 112 272 R270
SYMATTR InstName R39
SYMATTR Value 500
SYMBOL Res 240 144 R270
SYMATTR InstName R40
SYMATTR Value 2.2k
SYMBOL Res 384 256 R270
SYMATTR InstName R41
SYMATTR Value 11k
SYMBOL Res 656 256 R270
SYMATTR InstName R42
SYMATTR Value 1k
SYMBOL Res 768 144 R270
SYMATTR InstName R43
SYMATTR Value 4k
SYMBOL Cap -64 160 R270
SYMATTR InstName C18
SYMATTR Value 100p
SYMBOL Cap 48 272 R270
SYMATTR InstName C19
SYMATTR Value 1.8n
SYMBOL Cap 480 288 R0
SYMATTR InstName C20
SYMATTR Value 220p
SYMBOL Voltage -832 224 R0
SYMATTR Value SINE(0 6m 50k)
SYMATTR InstName V9
SYMBOL Res -240 128 R90
SYMATTR InstName R44
SYMATTR Value 10k
SYMBOL Res -432 208 R90
SYMATTR InstName R45
SYMATTR Value 1k
SYMBOL OpAmps/LT1057 -304 176 R0
SYMATTR InstName U19
SYMBOL OpAmps/LT1057 -32 176 R0
SYMATTR InstName U20
SYMBOL OpAmps/LT1057 304 176 R0
SYMATTR InstName U21
SYMBOL OpAmps/LT1057 800 192 R0
SYMATTR InstName U22
SYMBOL OpAmps/LT1057 -672 160 R0
SYMATTR InstName U23
SYMBOL OpAmps/LT1057 608 176 R0
SYMATTR InstName U24
SYMBOL Voltage -960 224 R0
SYMATTR Value SINE(0 2m 10k)
SYMATTR InstName V12
SYMBOL Res 240 256 R0
SYMATTR InstName R46
SYMATTR Value 2.2k
SYMBOL Res -544 384 R180
SYMATTR InstName R31
SYMATTR Value 50
SYMBOL Cap -560 208 R90
SYMATTR InstName C17
SYMATTR Value 100n
SYMBOL schottky 848 -192 R270
SYMATTR InstName D1
SYMBOL Cap 896 -208 R0
SYMATTR InstName C21
SYMATTR Value 4.7n
SYMBOL Cap 960 256 R0
SYMATTR InstName C22
SYMATTR Value 1n
SYMBOL schottky 912 272 R270
SYMATTR InstName D2
SYMBOL Res -416 -336 R90
SYMATTR InstName R1
SYMATTR Value 10k