Version 4
SHEET 1 880 680
WIRE -16 48 -176 48
WIRE 112 48 64 48
WIRE 368 48 112 48
WIRE 112 80 112 48
WIRE 368 96 368 48
WIRE 256 160 240 160
WIRE 368 160 336 160
WIRE 240 240 240 160
WIRE 240 240 112 240
WIRE 704 240 368 240
WIRE 784 240 784 224
WIRE 784 240 704 240
WIRE 704 272 704 240
WIRE -176 336 -176 48
WIRE 240 336 240 240
WIRE 256 336 240 336
WIRE 368 336 368 320
WIRE 368 336 336 336
WIRE 368 400 368 384
WIRE 112 416 112 320
WIRE 112 416 -176 416
WIRE 208 416 112 416
WIRE 368 416 368 400
WIRE 368 416 208 416
WIRE 704 416 704 352
WIRE 704 416 368 416
WIRE 208 432 208 416
FLAG 208 432 0
FLAG 784 224 Vo
SYMBOL res 96 64 R0
WINDOW 3 70 40 Left 2
SYMATTR Value 100k
SYMATTR InstName R1
SYMBOL res 96 144 R0
WINDOW 0 37 29 Left 2
WINDOW 3 -335 51 Left 2
SYMATTR InstName R2
SYMATTR Value {Rbass*(1 - 100**(k-1)) + 1 m}
SYMBOL res 96 224 R0
WINDOW 3 -273 46 Left 2
SYMATTR Value {Rbass*100**(k-1) + 1m}
SYMATTR InstName R3
SYMBOL res 352 144 R0
WINDOW 3 73 39 Left 2
SYMATTR Value {Rtreb*(1-(100**k)/100)+1m}
SYMATTR InstName R4
SYMBOL res 352 224 R0
SYMATTR InstName R5
SYMATTR Value {Rtreb*(100**k)/100+1m}
SYMBOL res 80 32 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R6
SYMATTR Value 40k
SYMBOL cap 352 96 R0
WINDOW 0 43 6 Left 2
WINDOW 3 42 33 Left 2
SYMATTR InstName C1
SYMATTR Value 330pF
SYMBOL cap 352 336 R0
WINDOW 0 45 24 Left 2
WINDOW 3 42 51 Left 2
SYMATTR InstName C3
SYMATTR Value 2.7nF
SYMBOL voltage -176 320 R0
WINDOW 0 7 110 Left 2
WINDOW 123 7 136 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value2 AC 1
SYMATTR Value ""
SYMBOL res 352 144 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R7
SYMATTR Value 2200k
SYMBOL res 352 320 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R8
SYMATTR Value 220k
SYMBOL res 688 256 R0
SYMATTR InstName R9
SYMATTR Value 1000k
TEXT -184 -144 Left 2 !.param Rbass=500k
TEXT -184 -96 Left 2 !.param Rtreb=250k
TEXT 104 -96 Left 2 !.ac oct 10 80 8000
TEXT 104 -144 Left 2 !.step param k 0 1 0.1111