* SPICE netlist
V1 Vcc 0 34
V2 Vin 0 SINE(16 {Volume} 1k) AC 0
V3 V+ 0 15
V4 0 V- 15
Q1 Vcc N005 N007 0 NPN
Q2 N019 I_mirror 0 0 NPN
Q3 N001 N001 I_mirror 0 NPN
Q4 N001 I_mirror N013 0 NPN
R1 Vin N001 {bias}
Q5 N019 I_mirror 0 0 NPN
R3 Vcc N005 10k
R4 N005 0 10k
R6 N013 0 1n
R_Load N017 N018 {Load_Z}
Q6 N019 I_mirror 0 0 NPN
Q7 N019 I_mirror 0 0 NPN
Q8 N019 I_mirror 0 0 NPN
Q9 Vcc N006 N012 0 NPN
R5 Vcc N006 10k
R7 N006 0 10k
Q10 N020 I_mirror_180 0 0 NPN
Q11 N020 I_mirror_180 0 0 NPN
Q12 N020 I_mirror_180 0 0 NPN
Q13 N020 I_mirror_180 0 0 NPN
Q14 N020 I_mirror_180 0 0 NPN
Q15 N002 N002 I_mirror_180 0 NPN
Q16 N002 I_mirror_180 N016 0 NPN
R9 Vin_180 N002 {bias}
R10 N016 0 1n
V5 Vin_180 0 SINE(16 {Volume} 1k 0 0 180) AC 0
Q17 Vcc N005 N008 0 NPN
Q18 Vcc N005 N009 0 NPN
Q19 Vcc N006 N011 0 NPN
Q20 Vcc N006 N010 0 NPN
R2 N007 N014 {R_e}
R8 N008 N014 {R_e}
R11 N009 N014 {R_e}
R12 N010 N015 {R_e}
R13 N011 N015 {R_e}
R14 N012 N015 {R_e}
R15 N017 N019 1n
R16 N018 N020 1n
V6 IMD_Test N003 SINE(16 {Volume} {IMD_Tone_1} 0 0 180)
V7 N003 0 SINE(16 {Volume} {IMD_Tone_2} 0 0 180)
V8 IMD_Test_180 N004 SINE(16 {Volume} {IMD_Tone_1})
V9 N004 0 SINE(16 {Volume} {IMD_Tone_2})
.tran 1
.param Volume 12
.param bias 220
.param Load_Z 32
.param R_e 4.7
.param IMD_Tone_1 1k
.param IMD_Tone_2 1.3k

* LTspice schematic (.asc)
Version 4
SHEET 1 3552 1088
WIRE -464 -464 -544 -464
WIRE -368 -464 -464 -464
WIRE 256 -464 176 -464
WIRE 352 -464 256 -464
WIRE -960 -432 -1056 -432
WIRE -1520 -416 -1616 -416
WIRE -960 -384 -960 -432
WIRE -544 -384 -544 -464
WIRE 352 -384 352 -464
WIRE -1520 -368 -1520 -416
WIRE -1184 -368 -1216 -368
WIRE -1056 -368 -1056 -432
WIRE -1056 -368 -1104 -368
WIRE -1744 -352 -1776 -352
WIRE -1616 -352 -1616 -416
WIRE -1616 -352 -1664 -352
WIRE 1520 -352 1520 -400
WIRE 1776 -352 1776 -400
WIRE -1056 -336 -1056 -368
WIRE -1024 -336 -1056 -336
WIRE -1616 -320 -1616 -352
WIRE -1584 -320 -1616 -320
WIRE -368 -272 -368 -464
WIRE -304 -272 -368 -272
WIRE -240 -272 -304 -272
WIRE 112 -272 64 -272
WIRE 176 -272 176 -464
WIRE 176 -272 112 -272
WIRE -960 -256 -960 -288
WIRE -912 -256 -960 -256
WIRE 1520 -256 1520 -272
WIRE 1776 -256 1776 -272
WIRE -1520 -240 -1520 -272
WIRE -1472 -240 -1520 -240
WIRE -544 -224 -544 -304
WIRE -432 -224 -544 -224
WIRE -368 -224 -432 -224
WIRE -304 -224 -368 -224
WIRE 176 -224 128 -224
WIRE 240 -224 176 -224
WIRE 352 -224 352 -304
WIRE 352 -224 240 -224
WIRE -1024 -192 -1024 -336
WIRE -1584 -176 -1584 -320
WIRE -544 -160 -544 -224
WIRE 352 -160 352 -224
WIRE 1520 -160 1520 -176
WIRE 1776 -160 1776 -176
WIRE -912 -144 -912 -256
WIRE -912 -144 -960 -144
WIRE -832 -144 -912 -144
WIRE -368 -144 -368 -176
WIRE -304 -144 -304 -176
WIRE -240 -144 -240 -176
WIRE 64 -144 64 -176
WIRE 112 -144 112 -176
WIRE 176 -144 176 -176
WIRE -1472 -128 -1472 -240
WIRE -1472 -128 -1520 -128
WIRE -1392 -128 -1472 -128
WIRE -1024 -64 -1024 -96
WIRE -304 -64 -368 -64
WIRE -240 -64 -304 -64
WIRE 112 -64 64 -64
WIRE 176 -64 112 -64
WIRE -1584 -48 -1584 -80
WIRE -544 -48 -544 -80
WIRE 352 -48 352 -80
WIRE -304 48 -304 -16
WIRE -128 48 -304 48
WIRE 112 48 112 -16
WIRE 112 48 -48 48
WIRE -304 176 -304 48
WIRE 112 176 112 48
WIRE -320 384 -384 384
WIRE -304 384 -304 256
WIRE -304 384 -320 384
WIRE -256 384 -304 384
WIRE -208 384 -256 384
WIRE -144 384 -208 384
WIRE 16 384 -48 384
WIRE 64 384 16 384
WIRE 112 384 112 256
WIRE 112 384 64 384
WIRE 128 384 112 384
WIRE 192 384 128 384
WIRE -448 432 -544 432
WIRE -384 432 -448 432
WIRE -320 432 -384 432
WIRE -272 432 -320 432
WIRE -208 432 -272 432
WIRE 80 432 16 432
WIRE 128 432 80 432
WIRE 192 432 128 432
WIRE 256 432 192 432
WIRE 352 432 256 432
WIRE -320 480 -384 480
WIRE -256 480 -320 480
WIRE -208 480 -256 480
WIRE -144 480 -208 480
WIRE 16 480 -48 480
WIRE 64 480 16 480
WIRE 128 480 64 480
WIRE 192 480 128 480
WIRE -384 544 -384 480
WIRE 192 544 192 480
FLAG 864 -304 Vcc
FLAG 864 -224 0
FLAG 1024 -224 0
FLAG 1024 -304 Vin
FLAG 1344 416 0
FLAG 1184 416 0
FLAG 1184 336 V+
FLAG 1344 336 V-
FLAG -464 -464 Vcc
FLAG -1216 -368 Vin
FLAG -384 544 0
FLAG -1024 16 0
FLAG -832 -144 I_mirror
FLAG -544 432 I_mirror
FLAG -544 -48 0
FLAG 352 -48 0
FLAG 256 -464 Vcc
FLAG 192 544 0
FLAG 352 432 I_mirror_180
FLAG -1776 -352 Vin_180
FLAG -1584 32 0
FLAG -1392 -128 I_mirror_180
FLAG 1024 -448 0
FLAG 1024 -528 Vin_180
FLAG 1520 -160 0
FLAG 1776 -160 0
FLAG 1520 -400 IMD_Test
FLAG 1776 -400 IMD_Test_180
SYMBOL voltage 864 -320 R0
SYMATTR InstName V1
SYMATTR Value 34
SYMBOL voltage 1024 -320 R0
SYMATTR Value SINE(16 {Volume} 1k)
SYMATTR Value2 AC 0
SYMATTR InstName V2
SYMBOL voltage 1184 320 R0
SYMATTR InstName V3
SYMATTR Value 15
SYMBOL voltage 1344 432 R180
SYMATTR InstName V4
SYMATTR Value 15
SYMBOL npn -432 -272 R0
SYMATTR InstName Q1
SYMBOL npn -448 384 R0
SYMATTR InstName Q2
SYMBOL npn -1024 -384 R0
SYMATTR InstName Q3
SYMBOL npn -960 -192 M0
SYMATTR InstName Q4
SYMBOL res -1200 -352 R270
SYMATTR InstName R1
SYMATTR Value {bias}
SYMBOL npn -320 384 R0
SYMATTR InstName Q5
SYMBOL res -560 -400 R0
SYMATTR InstName R3
SYMATTR Value 10k
SYMBOL res -560 -176 R0
SYMATTR InstName R4
SYMATTR Value 10k
SYMBOL res -1040 -80 R0
SYMATTR InstName R6
SYMATTR Value 1n
SYMBOL res -144 64 R270
SYMATTR InstName R_Load
SYMATTR Value {Load_Z}
SYMBOL npn -384 384 R0
SYMATTR InstName Q6
SYMBOL npn -272 384 R0
SYMATTR InstName Q7
SYMBOL npn -208 384 R0
SYMATTR InstName Q8
SYMBOL npn 240 -272 M0
SYMATTR InstName Q9
SYMBOL res 368 -400 M0
SYMATTR InstName R5
SYMATTR Value 10k
SYMBOL res 368 -176 M0
SYMATTR InstName R7
SYMATTR Value 10k
SYMBOL npn 256 384 M0
SYMATTR InstName Q10
SYMBOL npn 128 384 M0
SYMATTR InstName Q11
SYMBOL npn 192 384 M0
SYMATTR InstName Q12
SYMBOL npn 80 384 M0
SYMATTR InstName Q13
SYMBOL npn 16 384 M0
SYMATTR InstName Q14
SYMBOL npn -1584 -368 R0
SYMATTR InstName Q15
SYMBOL npn -1520 -176 M0
SYMATTR InstName Q16
SYMBOL res -1760 -336 R270
SYMATTR InstName R9
SYMATTR Value {bias}
SYMBOL res -1600 -64 R0
SYMATTR InstName R10
SYMATTR Value 1n
SYMBOL voltage 1024 -544 R0
SYMATTR Value SINE(16 {Volume} 1k 0 0 180)
SYMATTR Value2 AC 0
SYMATTR InstName V5
SYMBOL npn -368 -272 R0
SYMATTR InstName Q17
SYMBOL npn -304 -272 R0
SYMATTR InstName Q18
SYMBOL npn 176 -272 M0
SYMATTR InstName Q19
SYMBOL npn 128 -272 M0
SYMATTR InstName Q20
SYMBOL res -384 -160 R0
SYMATTR InstName R2
SYMATTR Value {R_e}
SYMBOL res -320 -160 R0
SYMATTR InstName R8
SYMATTR Value {R_e}
SYMBOL res -256 -160 R0
SYMATTR InstName R11
SYMATTR Value {R_e}
SYMBOL res 48 -160 R0
SYMATTR InstName R12
SYMATTR Value {R_e}
SYMBOL res 96 -160 R0
SYMATTR InstName R13
SYMATTR Value {R_e}
SYMBOL res 160 -160 R0
SYMATTR InstName R14
SYMATTR Value {R_e}
SYMBOL res -320 160 R0
SYMATTR InstName R15
SYMATTR Value 1n
SYMBOL res 96 160 R0
SYMATTR InstName R16
SYMATTR Value 1n
SYMBOL voltage 1520 -368 R0
SYMATTR InstName V6
SYMATTR Value SINE(16 {Volume} {IMD_Tone_1} 0 0 180)
SYMBOL voltage 1520 -272 R0
SYMATTR InstName V7
SYMATTR Value SINE(16 {Volume} {IMD_Tone_2} 0 0 180)
SYMBOL voltage 1776 -368 R0
SYMATTR InstName V8
SYMATTR Value SINE(16 {Volume} {IMD_Tone_1})
SYMBOL voltage 1776 -272 R0
SYMATTR InstName V9
SYMATTR Value SINE(16 {Volume} {IMD_Tone_2})