Version 4
SHEET 1 880 680
WIRE 352 -80 48 -80
WIRE 480 -80 352 -80
WIRE 352 -64 352 -80
WIRE 48 -16 48 -80
WIRE 352 16 352 0
WIRE 48 96 48 64
WIRE 208 96 48 96
WIRE 336 96 272 96
WIRE 368 96 336 96
WIRE 48 128 48 96
WIRE 0 176 -176 176
WIRE 480 192 480 -80
WIRE 16 224 -32 224
WIRE 336 224 336 96
WIRE -176 240 -176 176
WIRE 128 240 64 240
WIRE 128 256 128 240
WIRE -32 272 -32 224
WIRE 32 352 32 240
WIRE 128 352 128 336
WIRE 128 352 32 352
WIRE -176 400 -176 320
WIRE -32 400 -32 352
WIRE -32 400 -176 400
WIRE 128 400 128 352
WIRE 128 400 -32 400
WIRE 240 400 128 400
WIRE 336 400 336 304
WIRE 336 400 240 400
WIRE 480 400 480 272
WIRE 480 400 336 400
WIRE 240 432 240 400
FLAG 240 432 0
FLAG 352 16 0
FLAG 368 96 Out
IOPIN 368 96 Out
SYMBOL res 32 -32 R0
SYMATTR InstName R1
SYMATTR Value 100K
SYMBOL voltage 480 176 R0
WINDOW 3 41 45 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 40 72 Left 0
WINDOW 0 46 16 Left 0
SYMATTR Value 250
SYMATTR SpiceLine Rser=5000
SYMATTR InstName V1
SYMBOL triodeh 48 176 R0
WINDOW 0 70 -15 Left 0
WINDOW 38 120 12 Center 0
SYMATTR InstName U1
SYMATTR SpiceModel 12AX7DM
SYMBOL res -48 256 R0
SYMATTR InstName R2
SYMATTR Value 1K
SYMBOL voltage 128 240 R0
WINDOW 123 0 0 Left 0
WINDOW 39 24 132 Left 0
WINDOW 0 -13 57 Left 0
SYMATTR SpiceLine Rser=0.01
SYMATTR InstName V2
SYMATTR Value SINE(0 8.91 50)
SYMBOL voltage -176 224 R0
WINDOW 0 -16 58 Left 0
WINDOW 3 8 -23 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V3
SYMATTR Value SINE(0 0.5 20)
SYMBOL cap 272 80 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName C1
SYMATTR Value 47n
SYMBOL res 320 208 R0
SYMATTR InstName R3
SYMATTR Value 1e6
SYMBOL cap 336 -64 R0
WINDOW 0 44 21 Left 0
WINDOW 3 46 50 Left 0
SYMATTR InstName C2
SYMATTR Value 100µ
TEXT -16 424 Left 0 !.tran 15S startup uic