* SPICE netlist
V1 DAC 0 AC 1.0
R1 IN2 DAC 10K
R4 N003 V5 22K
R6 0 N005 6.8k
XU1 V5 IN2 V5 opamp Aol=100K GBW=3Meg ;pnba invin)noninvin)out
XU2 V6 N005 V6 opamp Aol=100K GBW=3Meg ;pnba invin)noninvin)out
R3 N002 N003 22K
C2 N004 N002 100n
C4 0 IN2 1n
C5 0 N003 470p
C6 0 N002 470p
R5 0 IN2 100k
C7 GA V6 100n
R7 0 GA 22k
XU3 N001 GA V4b opamp Aol=100K GBW=3Meg ;pnba invin)noninvin)out
R9 0 N001 51
R10 V4b N001 5.1k
C8 V4b N001 470p
R11 V4 V4b 1k
C9 0 V4 4.7n
R2 N005 N004 22K
C1 0 N005 470p
R8 N002 AFC 12K
.ac oct 25 10 100K
.include opamp.sub

* LTspice schematic (.asc)
Version 4.1
SHEET 1 2352 416
WIRE 808 -192 776 -192
WIRE 920 -192 872 -192
WIRE -472 -128 -536 -128
WIRE -392 -128 -472 -128
WIRE -280 -128 -312 -128
WIRE -632 -80 -760 -80
WIRE 216 -80 88 -80
WIRE 776 -80 776 -192
WIRE 808 -80 776 -80
WIRE 920 -80 920 -192
WIRE 920 -80 888 -80
WIRE 1000 -80 920 -80
WIRE 1064 -80 1000 -80
WIRE 776 0 776 -80
WIRE 824 0 776 0
WIRE 88 16 88 -80
WIRE 120 16 88 16
WIRE 920 16 920 -80
WIRE 920 16 888 16
WIRE 952 16 920 16
WIRE 1064 16 1032 16
WIRE 1112 16 1064 16
WIRE 1176 16 1112 16
WIRE -760 32 -760 -80
WIRE -728 32 -760 32
WIRE 216 32 216 -80
WIRE 216 32 184 32
WIRE 248 32 216 32
WIRE 600 32 248 32
WIRE 680 32 664 32
WIRE 728 32 680 32
WIRE 824 32 728 32
WIRE -632 48 -632 -80
WIRE -632 48 -664 48
WIRE -584 48 -632 48
WIRE -536 48 -584 48
WIRE -424 48 -456 48
WIRE -392 48 -424 48
WIRE -280 48 -280 -128
WIRE -280 48 -312 48
WIRE -264 48 -280 48
WIRE -168 48 -200 48
WIRE -56 48 -88 48
WIRE 72 48 -56 48
WIRE 120 48 72 48
WIRE -1096 64 -1176 64
WIRE -1032 64 -1096 64
WIRE -904 64 -952 64
WIRE -840 64 -904 64
WIRE -792 64 -840 64
WIRE -728 64 -792 64
WIRE -1176 96 -1176 64
WIRE -904 96 -904 64
WIRE -792 96 -792 64
WIRE -424 96 -424 48
WIRE -280 96 -280 48
WIRE -56 96 -56 48
WIRE 72 96 72 48
WIRE 680 96 680 32
WIRE 776 96 776 0
WIRE 1064 96 1064 16
WIRE -1176 208 -1176 176
WIRE -904 208 -904 160
WIRE -792 208 -792 176
WIRE -424 208 -424 160
WIRE -280 208 -280 160
WIRE -56 208 -56 160
WIRE 72 208 72 176
WIRE 680 208 680 176
WIRE 776 208 776 176
WIRE 1064 208 1064 160
FLAG -1176 208 0
FLAG 248 32 V6
FLAG -584 48 V5
FLAG -904 208 0
FLAG -424 208 0
FLAG -280 208 0
FLAG 72 208 0
FLAG -792 208 0
FLAG -472 -128 AFC
FLAG -1096 64 DAC
FLAG -840 64 IN2
FLAG 680 208 0
FLAG 728 32 GA
FLAG 776 208 0
FLAG 1112 16 V4
FLAG 1064 208 0
FLAG 1000 -80 V4b
FLAG -56 208 0
SYMBOL voltage -1176 80 R0
SYMATTR InstName V1
SYMATTR Value ""
SYMATTR Value2 AC 1.0
SYMBOL res -936 48 R90
SYMATTR InstName R1
SYMATTR Value 10K
SYMBOL res -440 32 R90
SYMATTR InstName R4
SYMATTR Value 22K
SYMBOL res 88 192 R180
SYMATTR InstName R6
SYMATTR Value 6.8k
SYMBOL OPAMPS\\OPAMP -696 -16 R0
SYMATTR InstName U1
SYMATTR SpiceLine2 GBW=3Meg
SYMBOL OPAMPS\\OPAMP 152 -32 R0
SYMATTR InstName U2
SYMATTR SpiceLine2 GBW=3Meg
SYMBOL res -296 32 R90
SYMATTR InstName R3
SYMATTR Value 22K
SYMBOL cap -200 32 R90
SYMATTR InstName C2
SYMATTR Value 100n
SYMBOL cap -920 160 M180
SYMATTR InstName C4
SYMATTR Value 1n
SYMBOL cap -440 160 M180
SYMATTR InstName C5
SYMATTR Value 470p
SYMBOL cap -296 160 M180
SYMATTR InstName C6
SYMATTR Value 470p
SYMBOL res -776 192 R180
SYMATTR InstName R5
SYMATTR Value 100k
SYMBOL cap 664 16 R90
SYMATTR InstName C7
SYMATTR Value 100n
SYMBOL res 696 192 R180
SYMATTR InstName R7
SYMATTR Value 22k
SYMBOL OPAMPS\\OPAMP 856 -48 R0
SYMATTR InstName U3
SYMATTR SpiceLine2 GBW=3Meg
SYMBOL res 792 192 R180
SYMATTR InstName R9
SYMATTR Value 51
SYMBOL res 904 -96 R90
SYMATTR InstName R10
SYMATTR Value 5.1k
SYMBOL cap 872 -208 R90
SYMATTR InstName C8
SYMATTR Value 470p
SYMBOL res 1048 0 R90
SYMATTR InstName R11
SYMATTR Value 1k
SYMBOL cap 1048 160 M180
SYMATTR InstName C9
SYMATTR Value 4.7n
SYMBOL res -72 32 R90
SYMATTR InstName R2
SYMATTR Value 22K
SYMBOL cap -72 160 M180
SYMATTR InstName C1
SYMATTR Value 470p
SYMBOL res -296 -144 R90
SYMATTR InstName R8
SYMATTR Value 12K