* SPICE netlist
Q1 N008 N011 N009 0 NPN
Q2 N011 N009 N012 0 NPN
R1 N010 N009 350
R2 N010 0 1
R3 N011 N008 4k
V1 N008 0 SINE(24 10 2)
R4 N003 N002 25
R5 N004 0 47
R6 N005 N001 1k
V2 0 N001 SINE(10 1m 20)
Q4 N005 N002 N006 0 PNP
Q3 N001 N005 N002 0 MJE350
V3 N004 N003 0
D1 N012 N013 D
V4 N013 N010 1.1
D2 N003 N007 D
V5 N007 N006 1.3
R7 P001 N006 22
D3 N003 P002 D
V6 P002 P001 1.1
Q5 N014 N017 N015 0 NPN
Q6 N017 N015 N016 0 NPN
R8 N016 N015 12.2
R9 N016 0 1
R10 N017 N014 6.6k
V7 N014 0 SINE(24 1 2)
R11 N017 N014 100k
.tran 1

* LTspice schematic (.asc)
Version 4
SHEET 1 2480 896
WIRE -488 -432 -632 -432
WIRE -344 -432 -488 -432
WIRE -8 -432 -248 -432
WIRE 120 -432 -8 -432
WIRE 264 -432 200 -432
WIRE 296 -432 264 -432
WIRE 456 -432 376 -432
WIRE -632 -384 -632 -432
WIRE 456 -384 456 -432
WIRE -8 -320 -8 -432
WIRE -632 -272 -632 -304
WIRE -488 -256 -488 -432
WIRE -440 -256 -488 -256
WIRE -296 -256 -296 -368
WIRE -296 -256 -360 -256
WIRE -56 -256 -296 -256
WIRE 56 -256 40 -256
WIRE 72 -256 56 -256
WIRE 184 -256 152 -256
WIRE 264 -256 264 -432
WIRE 264 -256 248 -256
WIRE 312 -256 264 -256
WIRE 456 -256 456 -304
WIRE 56 -160 56 -256
WIRE 72 -160 56 -160
WIRE 312 -160 312 -256
WIRE 312 -160 296 -160
WIRE 296 -48 152 -48
WIRE 440 -48 296 -48
WIRE 696 -48 536 -48
WIRE 824 -48 696 -48
WIRE 1048 -48 904 -48
WIRE 1240 -48 1048 -48
WIRE 152 0 152 -48
WIRE 1240 0 1240 -48
WIRE 696 64 696 -48
WIRE 152 112 152 80
WIRE 296 128 296 -48
WIRE 344 128 296 128
WIRE 488 128 488 16
WIRE 488 128 424 128
WIRE 648 128 488 128
WIRE 808 128 744 128
WIRE 904 128 872 128
WIRE 1048 128 1048 -48
WIRE 1048 128 984 128
WIRE 1240 128 1240 80
WIRE -1096 160 -1240 160
WIRE -952 160 -1096 160
WIRE -696 160 -856 160
WIRE -568 160 -696 160
WIRE -344 160 -488 160
WIRE -152 160 -344 160
WIRE -1240 208 -1240 160
WIRE -152 208 -152 160
WIRE -696 272 -696 160
WIRE -1240 320 -1240 288
WIRE -1096 336 -1096 160
WIRE -1048 336 -1096 336
WIRE -920 336 -968 336
WIRE -904 336 -904 224
WIRE -904 336 -920 336
WIRE -744 336 -904 336
WIRE -344 336 -344 160
WIRE -344 336 -648 336
WIRE -152 336 -152 288
WIRE -1096 448 -1096 336
WIRE -1048 448 -1096 448
WIRE -968 448 -984 448
WIRE -920 448 -920 336
WIRE -920 448 -968 448
FLAG 1240 128 0
FLAG 152 112 0
FLAG 456 -256 0
FLAG -632 -272 0
FLAG -152 336 0
FLAG -1240 320 0
SYMBOL npn 440 16 R270
SYMATTR InstName Q1
SYMBOL npn 648 64 M90
SYMATTR InstName Q2
SYMBOL res 920 -64 R90
SYMATTR InstName R1
SYMATTR Value 350
SYMBOL res 1224 -16 R0
SYMATTR InstName R2
SYMATTR Value 1
SYMBOL res 440 112 R90
SYMATTR InstName R3
SYMATTR Value 4k
SYMBOL voltage 152 -16 R0
SYMATTR InstName V1
SYMATTR Value SINE(24 10 2)
SYMBOL res 216 -448 R90
SYMATTR InstName R4
SYMATTR Value 25
SYMBOL res 440 -400 R0
SYMATTR InstName R5
SYMATTR Value 47
SYMBOL res -344 -272 R90
SYMATTR InstName R6
SYMATTR Value 1k
SYMBOL voltage -632 -288 R180
SYMATTR Value SINE(10 1m 20)
SYMATTR InstName V2
SYMBOL pnp -56 -320 M90
SYMATTR InstName Q4
SYMBOL pnp -344 -368 R270
SYMATTR InstName Q3
SYMATTR Value MJE350
SYMBOL voltage 392 -432 R90
SYMATTR InstName V3
SYMATTR Value 0
SYMBOL LED 808 144 R270
SYMATTR InstName D1
SYMBOL voltage 888 128 R270
SYMATTR InstName V4
SYMATTR Value 1.1
SYMBOL LED 248 -240 M270
SYMATTR InstName D2
SYMBOL voltage 168 -256 M270
SYMATTR InstName V5
SYMATTR Value 1.3
SYMBOL res 168 -176 R90
SYMATTR InstName R7
SYMATTR Value 22
SYMBOL LED 296 -144 M270
SYMATTR InstName D3
SYMBOL voltage 248 -160 M270
SYMATTR InstName V6
SYMATTR Value 1.1
SYMBOL npn -952 224 R270
SYMATTR InstName Q5
SYMBOL npn -744 272 M90
SYMATTR InstName Q6
SYMBOL res -472 144 R90
SYMATTR InstName R8
SYMATTR Value 12.2
SYMBOL res -168 192 R0
SYMATTR InstName R9
SYMATTR Value 1
SYMBOL res -952 320 R90
SYMATTR InstName R10
SYMATTR Value 6.6k
SYMBOL voltage -1240 192 R0
SYMATTR InstName V7
SYMATTR Value SINE(24 1 2)
SYMBOL res -952 432 R90
SYMATTR InstName R11
SYMATTR Value 100k