* SPICE netlist
R1 C1 N001 4
R2 C1 N002 4
R3 C1 N003 4
R4 C1 N004 4
R5 C1 N005 4
R6 C1 N006 4
R7 C1 N007 4
R8 C2 N001 4
R9 C2 N002 4
R10 C2 N003 4
R11 C2 N004 4
R12 C2 N005 4
R13 C2 N006 4
R14 C2 N007 4
R15 C3 N001 4
R16 C3 N002 4
R17 C3 N003 4
R18 C3 N004 4
R19 C3 N005 4
R20 C3 N006 4
R21 C3 N007 4
R22 C4 N001 4
R23 C4 N002 4
R24 C4 N003 4
R25 C4 N004 4
R26 C4 N005 4
R27 C4 N006 4
R28 C4 N007 4
Vsupp 6V 0 6
Rpu2 6V C2 {Rpu}
Rpu3 6V C3 {Rpu}
Rpu4 6V C4 {Rpu}
V1 6V N001 0
V2 C1 0 0
Rpu1 6V C1 {Rpu}
.op
.param Rpu 3.3

* LTspice schematic (.asc)
Version 4
SHEET 1 864 944
WIRE -64 -312 -64 -376
WIRE 96 -312 96 -376
WIRE 256 -312 256 -376
WIRE 416 -312 416 -376
WIRE -256 -248 -272 -248
WIRE -144 -248 -176 -248
WIRE 16 -248 -144 -248
WIRE 176 -248 16 -248
WIRE 336 -248 176 -248
WIRE -144 -200 -144 -248
WIRE -64 -200 -64 -312
WIRE 16 -200 16 -248
WIRE 96 -200 96 -312
WIRE 176 -200 176 -248
WIRE 256 -200 256 -312
WIRE 336 -200 336 -248
WIRE 416 -200 416 -312
WIRE -144 -168 -272 -168
WIRE 16 -168 -144 -168
WIRE 176 -168 16 -168
WIRE 336 -168 176 -168
WIRE -144 -120 -144 -168
WIRE -64 -120 -64 -200
WIRE 16 -120 16 -168
WIRE 96 -120 96 -200
WIRE 176 -120 176 -168
WIRE 256 -120 256 -200
WIRE 336 -120 336 -168
WIRE 416 -120 416 -200
WIRE -144 -88 -272 -88
WIRE 16 -88 -144 -88
WIRE 176 -88 16 -88
WIRE 336 -88 176 -88
WIRE -144 -40 -144 -88
WIRE -64 -40 -64 -120
WIRE 16 -40 16 -88
WIRE 96 -40 96 -120
WIRE 176 -40 176 -88
WIRE 256 -40 256 -120
WIRE 336 -40 336 -88
WIRE 416 -40 416 -120
WIRE -144 -8 -272 -8
WIRE 16 -8 -144 -8
WIRE 176 -8 16 -8
WIRE 336 -8 176 -8
WIRE -144 40 -144 -8
WIRE -64 40 -64 -40
WIRE 16 40 16 -8
WIRE 96 40 96 -40
WIRE 176 40 176 -8
WIRE 256 40 256 -40
WIRE 336 40 336 -8
WIRE 416 40 416 -40
WIRE -144 72 -272 72
WIRE 16 72 -144 72
WIRE 176 72 16 72
WIRE 336 72 176 72
WIRE -144 120 -144 72
WIRE -64 120 -64 40
WIRE 16 120 16 72
WIRE 96 120 96 40
WIRE 176 120 176 72
WIRE 256 120 256 40
WIRE 336 120 336 72
WIRE 416 120 416 40
WIRE -144 152 -272 152
WIRE 16 152 -144 152
WIRE 176 152 16 152
WIRE 336 152 176 152
WIRE -144 200 -144 152
WIRE -64 200 -64 120
WIRE 16 200 16 152
WIRE 96 200 96 120
WIRE 176 200 176 152
WIRE 256 200 256 120
WIRE 336 200 336 152
WIRE 416 200 416 120
WIRE -144 232 -272 232
WIRE 16 232 -144 232
WIRE 176 232 16 232
WIRE 336 232 176 232
WIRE -144 280 -144 232
WIRE -64 280 -64 200
WIRE 16 280 16 232
WIRE 96 280 96 200
WIRE 176 280 176 232
WIRE 256 280 256 200
WIRE 336 280 336 232
WIRE 416 280 416 200
WIRE -64 360 -64 280
WIRE 96 392 96 280
WIRE 256 392 256 280
WIRE 416 392 416 280
WIRE -64 472 -64 440
FLAG -432 -296 0
FLAG -432 -376 6V
FLAG -272 -248 6V
FLAG -64 472 0
FLAG -64 -312 C1
FLAG 96 -312 C2
FLAG 256 -312 C3
FLAG 416 -312 C4
FLAG 96 -456 6V
FLAG 256 -456 6V
FLAG 416 -456 6V
FLAG -64 -456 6V
SYMBOL res -48 -216 R90
SYMATTR InstName R1
SYMATTR Value 4
SYMBOL res -48 -136 R90
SYMATTR InstName R2
SYMATTR Value 4
SYMBOL res -48 -56 R90
SYMATTR InstName R3
SYMATTR Value 4
SYMBOL res -48 24 R90
SYMATTR InstName R4
SYMATTR Value 4
SYMBOL res -48 104 R90
SYMATTR InstName R5
SYMATTR Value 4
SYMBOL res -48 184 R90
SYMATTR InstName R6
SYMATTR Value 4
SYMBOL res -48 264 R90
SYMATTR InstName R7
SYMATTR Value 4
SYMBOL res 112 -216 R90
SYMATTR InstName R8
SYMATTR Value 4
SYMBOL res 112 -136 R90
SYMATTR InstName R9
SYMATTR Value 4
SYMBOL res 112 -56 R90
SYMATTR InstName R10
SYMATTR Value 4
SYMBOL res 112 24 R90
SYMATTR InstName R11
SYMATTR Value 4
SYMBOL res 112 104 R90
SYMATTR InstName R12
SYMATTR Value 4
SYMBOL res 112 184 R90
SYMATTR InstName R13
SYMATTR Value 4
SYMBOL res 112 264 R90
SYMATTR InstName R14
SYMATTR Value 4
SYMBOL res 272 -216 R90
SYMATTR InstName R15
SYMATTR Value 4
SYMBOL res 272 -136 R90
SYMATTR InstName R16
SYMATTR Value 4
SYMBOL res 272 -56 R90
SYMATTR InstName R17
SYMATTR Value 4
SYMBOL res 272 24 R90
SYMATTR InstName R18
SYMATTR Value 4
SYMBOL res 272 104 R90
SYMATTR InstName R19
SYMATTR Value 4
SYMBOL res 272 184 R90
SYMATTR InstName R20
SYMATTR Value 4
SYMBOL res 272 264 R90
SYMATTR InstName R21
SYMATTR Value 4
SYMBOL res 432 -216 R90
SYMATTR InstName R22
SYMATTR Value 4
SYMBOL res 432 -136 R90
SYMATTR InstName R23
SYMATTR Value 4
SYMBOL res 432 -56 R90
SYMATTR InstName R24
SYMATTR Value 4
SYMBOL res 432 24 R90
SYMATTR InstName R25
SYMATTR Value 4
SYMBOL res 432 104 R90
SYMATTR InstName R26
SYMATTR Value 4
SYMBOL res 432 184 R90
SYMATTR InstName R27
SYMATTR Value 4
SYMBOL res 432 264 R90
SYMATTR InstName R28
SYMATTR Value 4
SYMBOL voltage -432 -392 R0
SYMATTR InstName Vsupp
SYMATTR Value 6
SYMBOL res 80 -472 R0
SYMATTR InstName Rpu2
SYMATTR Value {Rpu}
SYMBOL res 240 -472 R0
SYMATTR InstName Rpu3
SYMATTR Value {Rpu}
SYMBOL res 400 -472 R0
SYMATTR InstName Rpu4
SYMATTR Value {Rpu}
SYMBOL voltage -272 -248 R270
SYMATTR InstName V1
SYMATTR Value 0
SYMBOL voltage -64 344 R0
SYMATTR InstName V2
SYMATTR Value 0
SYMBOL res -80 -472 R0
SYMATTR InstName Rpu1
SYMATTR Value {Rpu}