* non-feedback pp mosfet amp
vsupply+ vdd 0 dc 20V
vsupply- vss 0 dc -20V
* input for low distortion output
v1 vinc 0 dc 0 ac 1 sin 0 0.1 1kHz
* input for soft-clipping output
*v1 vinc 0 dc 0 ac 1 sin 0 0.182 1kHz
*feedback network commented out
*ri vin vinc 1k
*rf vinc vout 20k
c1 vinc vbiasm1 330u
c2 vinc vbiasm2 330u
r1 vdd vbiasm1 60k
r2 vbiasm1 vss 390k
r5 vbiasm1 vgm1 100
m1 vout vgm1 vdd vdd pchpwr
r4 vss vbiasm2 60k
r3 vbiasm2 vdd 390k
r6 vbiasm2 vgm2 100
m2 vout vgm2 vss vss nchpwr
rl vout 0 8
* matched n-ch and p-ch mosfet models somewhat based on irfp240
.model pchpwr pmos(level=3 vto=-3 kp=10
+      RD=279.3M RS=76.83M IS=2.08P 
+      CBD=1.534N CGSO=961.9P CGDO=138.4P 
+      )
.model nchpwr nmos(level=3 vto=3 kp=10
+      RD=279.3M RS=76.83M IS=2.08P 
+      CBD=1.534N CGSO=961.9P CGDO=138.4P 
+      )
.end
.control
set fourgridsize=1024
set nfreqs=16
set polydegree=3
op
print all
tran 1u 10m 0 1u
fourier 1k vout
*ac dec 81 10 1g
*plot db(vout)
.endc