* SPICE netlist
Q1 N001 3 N005 0 NPN
Q2 N001 2 N006 0 NPN
Q3 N010 N008 N005 0 PNP
Q4 N011 N008 N006 0 PNP
Q5 N010 N014 1 0 NPN
Q6 N011 N014 5 0 NPN
Q7 7 N010 N014 0 NPN
R1 1 4 1k
R2 5 4 1k
R3 N014 4 50k
R4 N017 4 5k
Q8 N001 N001 7 0 PNP
Q9 N008 N001 7 0 PNP
Q10 N008 N012 N017 0 NPN
Q11 N012 N012 4 0 NPN
Q12 N002 N002 7 0 PNP
R5 N002 N012 39k
Q13 N003 N002 7 0 PNP
Q14 7 N003 N007 0 NPN
Q15 N003 N007 6 0 NPN
C1 N003 N011 30pF
R7 N003 N004 4.5k
R8 N009 N004 7.5k
Q16 N003 N004 N009 0 NPN
R9 N007 6 25
R10 6 N015 50
R11 N016 4 50
R12 N013 4 50k
Q17 N009 N013 N016 0 NPN
Q22 N011 N016 4 0 NPN
Q18 N009 N011 N013 0 NPN
Q20 4 N009 N015 0 PNP

* LTspice schematic (.asc)
Version 4
SHEET 1 1536 1104
WIRE -464 -376 -480 -376
WIRE -144 -376 -464 -376
WIRE -64 -376 -64 -552
WIRE -64 -376 -144 -376
WIRE 16 -376 -64 -376
WIRE 288 -376 16 -376
WIRE 496 -376 288 -376
WIRE -464 -360 -464 -376
WIRE -144 -360 -144 -376
WIRE 16 -360 16 -376
WIRE 288 -360 288 -376
WIRE -208 -312 -400 -312
WIRE 160 -312 80 -312
WIRE 224 -312 160 -312
WIRE 496 -296 496 -376
WIRE -464 -248 -464 -264
WIRE -464 -248 -560 -248
WIRE -400 -248 -400 -312
WIRE -400 -248 -464 -248
WIRE 288 -248 288 -264
WIRE 320 -248 288 -248
WIRE 416 -248 320 -248
WIRE 432 -248 416 -248
WIRE -560 -232 -560 -248
WIRE -400 -232 -400 -248
WIRE 16 -232 16 -264
WIRE 160 -232 160 -312
WIRE 160 -232 16 -232
WIRE 16 -200 16 -232
WIRE -624 -184 -768 -184
WIRE -304 -184 -304 -552
WIRE -304 -184 -336 -184
WIRE 320 -184 320 -248
WIRE 320 -184 112 -184
WIRE 208 -136 192 -136
WIRE 320 -136 320 -184
WIRE 320 -136 288 -136
WIRE 416 -136 416 -248
WIRE 320 -120 320 -136
WIRE 112 -104 112 -184
WIRE -560 -88 -560 -136
WIRE -400 -88 -400 -136
WIRE 496 -88 496 -200
WIRE 496 -88 480 -88
WIRE 192 -72 192 -136
WIRE 256 -72 192 -72
WIRE -464 -40 -496 -40
WIRE -144 -40 -144 -264
WIRE -144 -40 -464 -40
WIRE 496 -40 496 -88
WIRE 192 -8 192 -72
WIRE 208 -8 192 -8
WIRE 320 -8 320 -24
WIRE 320 -8 288 -8
WIRE -480 56 -480 -376
WIRE 320 56 320 -8
WIRE 320 56 208 56
WIRE 384 56 320 56
WIRE 416 56 416 -40
WIRE 496 56 496 40
WIRE 496 56 416 56
WIRE 496 88 496 56
WIRE 768 88 496 88
WIRE -560 104 -560 8
WIRE -544 104 -560 104
WIRE -400 104 -400 8
WIRE 112 104 112 -40
WIRE 112 104 -400 104
WIRE 144 104 112 104
WIRE 496 120 496 88
WIRE 320 152 320 56
WIRE 16 168 16 -120
WIRE 16 168 -64 168
WIRE -560 184 -560 104
WIRE -400 184 -400 104
WIRE -144 184 -144 -40
WIRE 16 184 16 168
WIRE 208 200 208 152
WIRE 256 200 208 200
WIRE -480 232 -480 152
WIRE -480 232 -496 232
WIRE -464 232 -480 232
WIRE -64 232 -64 168
WIRE -64 232 -80 232
WIRE -48 232 -64 232
WIRE 112 232 112 104
WIRE 496 232 496 200
WIRE 320 280 320 248
WIRE 320 280 176 280
WIRE 384 280 384 56
WIRE 432 280 384 280
WIRE -560 296 -560 280
WIRE -560 296 -768 296
WIRE -400 296 -400 280
WIRE -304 296 -400 296
WIRE -560 328 -560 296
WIRE -480 328 -480 232
WIRE -400 328 -400 296
WIRE -144 328 -144 280
WIRE 208 328 208 200
WIRE 320 328 320 280
WIRE -560 424 -560 408
WIRE -480 424 -480 408
WIRE -480 424 -560 424
WIRE -400 424 -400 408
WIRE -400 424 -480 424
WIRE -144 424 -144 408
WIRE -144 424 -400 424
WIRE -64 424 -144 424
WIRE 16 424 16 280
WIRE 16 424 -64 424
WIRE 112 424 112 328
WIRE 112 424 16 424
WIRE 208 424 208 408
WIRE 208 424 112 424
WIRE 320 424 320 408
WIRE 320 424 208 424
WIRE 496 424 496 328
WIRE 496 424 320 424
WIRE -64 536 -64 424
WIRE -304 552 -304 296
FLAG -768 -184 3
FLAG -304 -552 2
FLAG 768 88 6
FLAG -64 536 4
FLAG -64 -552 7
FLAG -768 296 1
FLAG -304 552 5
SYMBOL npn -624 -232 R0
SYMATTR InstName Q1
SYMBOL npn -336 -232 M0
SYMATTR InstName Q2
SYMBOL pnp -496 8 R180
SYMATTR InstName Q3
SYMBOL pnp -464 8 M180
SYMATTR InstName Q4
SYMBOL npn -496 184 M0
SYMATTR InstName Q5
SYMBOL npn -464 184 R0
SYMATTR InstName Q6
SYMBOL npn -544 56 R0
SYMATTR InstName Q7
SYMBOL res -576 312 R0
SYMATTR InstName R1
SYMATTR Value 1k
SYMBOL res -416 312 R0
SYMATTR InstName R2
SYMATTR Value 1k
SYMBOL res -496 312 R0
SYMATTR InstName R3
SYMATTR Value 50k
SYMBOL res -160 312 R0
SYMATTR InstName R4
SYMATTR Value 5k
SYMBOL pnp -400 -264 R180
SYMATTR InstName Q8
SYMBOL pnp -208 -264 M180
SYMATTR InstName Q9
SYMBOL npn -80 184 M0
SYMATTR InstName Q10
SYMBOL npn -48 184 R0
SYMATTR InstName Q11
SYMBOL pnp 80 -264 R180
SYMATTR InstName Q12
SYMBOL res 0 -216 R0
SYMATTR InstName R5
SYMATTR Value 39k
SYMBOL pnp 224 -264 M180
SYMATTR InstName Q13
SYMBOL npn 432 -296 R0
SYMATTR InstName Q14
SYMBOL npn 480 -136 M0
SYMATTR InstName Q15
SYMBOL cap 96 -104 R0
SYMATTR InstName C1
SYMATTR Value 30pF
SYMBOL res 304 -152 R90
SYMATTR InstName R7
SYMATTR Value 4.5k
SYMBOL res 304 -24 R90
SYMATTR InstName R8
SYMATTR Value 7.5k
SYMBOL npn 256 -120 R0
SYMATTR InstName Q16
SYMBOL res 480 -56 R0
SYMATTR InstName R9
SYMATTR Value 25
SYMBOL res 480 104 R0
SYMATTR InstName R10
SYMATTR Value 50
SYMBOL res 304 312 R0
SYMATTR InstName R11
SYMATTR Value 50
SYMBOL res 192 312 R0
SYMATTR InstName R12
SYMATTR Value 50k
SYMBOL npn 256 152 R0
SYMATTR InstName Q17
SYMBOL npn 176 232 M0
SYMATTR InstName Q22
SYMBOL npn 144 56 R0
SYMATTR InstName Q18
SYMBOL pnp 432 328 M180
SYMATTR InstName Q20