* SPICE netlist
R3 0 N014 10k
V1 N001 0 25
V2 0 N023 25
XU1 N014 N002 N001 N023 N007 LT1001 ;pnba In+)In-)V+)V-)OUT
V3 N008 0 1
R1 N002 N008 10k
XU2 N015 N003 N001 N023 N011 LT1001 ;pnba In+)In-)V+)V-)OUT
Q1 N002 0 N005 0 BC547B
R2 N004 N007 15.7k
R4 0 N004 1k
Q2 N003 N004 N005 0 BC547B
R5 N011 N005 220
R6 0 N015 10k
V4 N013 0 1 AC 1
R7 N003 N013 10k
C1 N007 N002 10p
C2 N003 N011 10p
R8 0 N017 10k
XU3 N017 N009 N001 N023 N010 LT1001 ;pnba In+)In-)V+)V-)OUT
XU4 N018 N012 N001 N023 N006 LT1001 ;pnba In+)In-)V+)V-)OUT
Q3 N009 0 N022 0 BC547B
R9 N021 N020 15.7k
R10 0 N021 1k
Q4 N012 N021 N022 0 BC547B
R11 N010 N022 220
R12 0 N018 10k
V5 N016 0 1
R13 N009 N016 10k
C3 N010 N009 100p
C4 N006 N012 100p
R14 N006 N012 10k
XU5 0 N019 N001 N023 N020 LT1001 ;pnba In+)In-)V+)V-)OUT
R15 N020 N019 10.7k
R24 N019 N007 10k
.dc V3 -1 10 10m
;tran 0 10m 0 1u
;ac dec 1001 1 100meg

* LTspice schematic (.asc)
Version 4
SHEET 1 2608 784
WIRE -408 -392 -952 -392
WIRE 8 -392 -408 -392
WIRE 632 -392 8 -392
WIRE 1128 -392 632 -392
WIRE 1304 -392 1128 -392
WIRE -792 -328 -1048 -328
WIRE -456 -328 -696 -328
WIRE -792 -312 -792 -328
WIRE -696 -312 -696 -328
WIRE -856 -264 -872 -264
WIRE -616 -264 -632 -264
WIRE -456 -248 -456 -328
WIRE -456 -248 -472 -248
WIRE -872 -232 -872 -264
WIRE -744 -216 -792 -216
WIRE -696 -216 -744 -216
WIRE 1208 -200 1064 -200
WIRE -1048 -184 -1048 -328
WIRE -1000 -184 -1048 -184
WIRE -904 -184 -936 -184
WIRE 1304 -168 1304 -392
WIRE -1192 -152 -1304 -152
WIRE -1048 -152 -1048 -184
WIRE -1048 -152 -1112 -152
WIRE 584 -152 536 -152
WIRE 680 -152 648 -152
WIRE -1304 -136 -1304 -152
WIRE -536 -136 -536 -248
WIRE -536 -136 -744 -136
WIRE -344 -136 -536 -136
WIRE 1000 -136 1000 -200
WIRE 1016 -136 1000 -136
WIRE 1208 -136 1208 -200
WIRE 1208 -136 1096 -136
WIRE -952 -120 -952 -392
WIRE -408 -120 -408 -392
WIRE -1048 -104 -1048 -152
WIRE -984 -104 -1048 -104
WIRE -552 -104 -584 -104
WIRE -456 -104 -456 -248
WIRE -456 -104 -472 -104
WIRE -440 -104 -456 -104
WIRE -904 -88 -904 -184
WIRE -904 -88 -920 -88
WIRE -888 -88 -904 -88
WIRE -792 -88 -808 -88
WIRE -616 -88 -616 -264
WIRE -616 -88 -792 -88
WIRE -344 -88 -344 -136
WIRE -344 -88 -376 -88
WIRE 632 -88 632 -392
WIRE -984 -72 -1016 -72
WIRE -440 -72 -488 -72
WIRE 392 -72 344 -72
WIRE 488 -72 472 -72
WIRE 536 -72 536 -152
WIRE 536 -72 488 -72
WIRE 600 -72 536 -72
WIRE 1128 -72 1128 -392
WIRE 1304 -72 1304 -88
WIRE -792 -56 -792 -88
WIRE -488 -56 -488 -72
WIRE 680 -56 680 -152
WIRE 680 -56 664 -56
WIRE 1000 -56 1000 -136
WIRE 1000 -56 840 -56
WIRE 1096 -56 1000 -56
WIRE 1304 -56 1304 -72
WIRE -584 -40 -584 -104
WIRE 600 -40 568 -40
WIRE 1208 -40 1208 -136
WIRE 1208 -40 1160 -40
WIRE -1016 -24 -1016 -72
WIRE 568 -24 568 -40
WIRE 1096 -24 1048 -24
WIRE -1304 -8 -1304 -56
WIRE 344 -8 344 -72
WIRE 1048 -8 1048 -24
WIRE 24 8 -104 8
WIRE 120 8 88 8
WIRE -792 56 -792 24
WIRE -488 56 -488 24
WIRE -1016 72 -1016 56
WIRE -584 72 -584 40
WIRE 568 72 568 56
WIRE -104 104 -104 8
WIRE 40 104 -104 104
WIRE 120 104 120 8
WIRE 344 104 344 72
WIRE 1048 104 1048 72
WIRE 488 120 488 -72
WIRE 840 120 840 -56
WIRE 8 168 8 -392
WIRE 424 168 408 168
WIRE 936 168 904 168
WIRE 952 168 936 168
WIRE 1096 168 1032 168
WIRE -104 184 -104 104
WIRE -24 184 -104 184
WIRE 120 200 120 104
WIRE 120 200 40 200
WIRE 408 200 408 168
WIRE 936 200 936 168
WIRE -24 216 -56 216
WIRE 792 216 488 216
WIRE 840 216 792 216
WIRE -56 232 -56 216
WIRE -904 264 -904 -88
WIRE -248 264 -904 264
WIRE -104 264 -104 184
WIRE -104 264 -168 264
WIRE 680 296 680 -56
WIRE 792 296 680 296
WIRE 936 312 936 280
WIRE -952 344 -952 -56
WIRE -408 344 -408 -56
WIRE -408 344 -952 344
WIRE 8 344 8 232
WIRE 8 344 -408 344
WIRE 632 344 632 -24
WIRE 632 344 8 344
WIRE 1128 344 1128 -8
WIRE 1128 344 632 344
WIRE 1304 344 1304 24
WIRE 1304 344 1128 344
WIRE 120 392 120 200
WIRE 1096 392 1096 168
WIRE 1096 392 120 392
FLAG -1304 -8 0
FLAG -1016 72 0
FLAG 1304 -72 0
FLAG -792 56 0
FLAG -488 56 0
FLAG -584 72 0
FLAG -872 -232 0
FLAG 568 72 0
FLAG 936 312 0
FLAG 1048 104 0
FLAG 344 104 0
FLAG 408 200 0
FLAG -56 232 0
SYMBOL res -1000 72 R180
SYMATTR InstName R3
SYMATTR Value 10k
SYMBOL voltage 1304 -184 R0
SYMATTR InstName V1
SYMATTR Value 25
SYMBOL voltage 1304 -72 R0
SYMATTR InstName V2
SYMATTR Value 25
SYMBOL Opamps\\LT1001A -952 -152 R0
SYMATTR InstName U1
SYMBOL voltage -1304 -152 R0
SYMATTR InstName V3
SYMATTR Value 1
SYMBOL res -1096 -168 R90
SYMATTR InstName R1
SYMATTR Value 10k
SYMBOL Opamps\\LT1001A -408 -152 R0
SYMATTR InstName U2
SYMBOL npn -856 -312 R0
SYMATTR InstName Q1
SYMATTR Value BC547B
SYMBOL res -792 -104 R90
SYMATTR InstName R2
SYMATTR Value 15.7k
SYMBOL res -776 40 R180
SYMATTR InstName R4
SYMATTR Value 1k
SYMBOL npn -632 -312 M0
SYMATTR InstName Q2
SYMATTR Value BC547B
SYMBOL res -728 -120 R180
SYMATTR InstName R5
SYMATTR Value 220
SYMBOL res -472 40 R180
SYMATTR InstName R6
SYMATTR Value 10k
SYMBOL voltage -584 -56 R0
SYMATTR InstName V4
SYMATTR Value 1
SYMATTR Value2 AC 1
SYMBOL res -456 -120 R90
SYMATTR InstName R7
SYMATTR Value 10k
SYMBOL cap -936 -200 R90
SYMATTR InstName C1
SYMATTR Value 10p
SYMBOL cap -472 -264 R90
SYMATTR InstName C2
SYMATTR Value 10p
SYMBOL res 584 72 R180
SYMATTR InstName R8
SYMATTR Value 10k
SYMBOL Opamps\\LT1001A 632 -120 R0
SYMATTR InstName U3
SYMBOL Opamps\\LT1001A 1128 -104 R0
SYMATTR InstName U4
SYMBOL npn 424 120 R0
SYMATTR InstName Q3
SYMATTR Value BC547B
SYMBOL res 936 152 M90
SYMATTR InstName R9
SYMATTR Value 15.7k
SYMBOL res 920 296 M180
SYMATTR InstName R10
SYMATTR Value 1k
SYMBOL npn 904 120 M0
SYMATTR InstName Q4
SYMATTR Value BC547B
SYMBOL res 808 312 R180
SYMATTR InstName R11
SYMATTR Value 220
SYMBOL res 1064 88 R180
SYMATTR InstName R12
SYMATTR Value 10k
SYMBOL voltage 344 -24 R0
SYMATTR InstName V5
SYMATTR Value 1
SYMBOL res 488 -88 R90
SYMATTR InstName R13
SYMATTR Value 10k
SYMBOL cap 648 -168 R90
SYMATTR InstName C3
SYMATTR Value 100p
SYMBOL cap 1064 -216 R90
SYMATTR InstName C4
SYMATTR Value 100p
SYMBOL res 1112 -152 R90
SYMATTR InstName R14
SYMATTR Value 10k
SYMBOL Opamps\\LT1001A 8 136 R0
SYMATTR InstName U5
SYMBOL res 136 88 R90
SYMATTR InstName R15
SYMATTR Value 10.7k
SYMBOL res -152 248 R90
SYMATTR InstName R24
SYMATTR Value 10k