• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Vacuum Tube SPICE Models

Ex-Moderator
Joined 2011
Try this:

Code:
.SUBCKT NU6P1 1 2 3
+params: MU= 18.10 EX= 4.080 KG1=4270851.9 KP=451.94 KVB= 4.2 VCT= 0.00 RGI=330k CCG=9.1P CGP=2.5P CCP=4.3P
E1 7 0 VALUE= 
+{V(1,3)/KP*LOG(1+EXP(KP*(1/MU+V(2,3)/SQRT(KVB+V(1,3)*V(1,3)))))} 
RE1 7 0 1G 
G1 1 3 VALUE={(PWR(V(7),EX)+PWRS(V(7),EX))/KG1} 
RCP 1 3 1G ; TO AVOID FLOATING NODES IN MU-FOLLOWER 
C1 2 3 {CCG} ; CATHODE-GRID 
C2 2 1 {CGP} ; GRID=PLATE 
C3 1 3 {CCP} ; CATHODE-PLATE 
D3 5 3 DX ; FOR GRID CURRENT 
R1 2 5 {RGI} ; FOR GRID CURRENT 
.MODEL DX D(IS=1N RS=1 CJO=10PF TT=1N) 
.ENDS
 
Ex-Moderator
Joined 2011
6BN11 SPICE Model

Code:
*
* Generic pentode model: 6BN11_AN
* Copyright 2003--2008 by Ayumi Nakabayashi, All rights reserved.
* Version 3.10, Generated on Sat Nov 01 18:19:03 2014
*                Plate
*                | Screen Grid
*                | |  Control Grid
*                | |  |  Cathode
*                | |  |  |
.SUBCKT 6BN11_AN A G2 G1 K
BGG   GG   0 V=V(G1,K)+0.80333486
BM1   M1   0 V=(0.016690499*(URAMP(V(G2,K))+1e-10))**-1.028498
BM2   M2   0 V=(0.59323756*(URAMP(V(GG)+URAMP(V(G2,K))/24.370897)))**2.528498
BP    P    0 V=0.0032099434*(URAMP(V(GG)+URAMP(V(G2,K))/41.081176))**1.5
BIK   IK   0 V=U(V(GG))*V(P)+(1-U(V(GG)))*0.0021774044*V(M1)*V(M2)
BIG   IG   0 V=0.0016049717*URAMP(V(G1,K))**1.5*(URAMP(V(G1,K))/(URAMP(V(A,K))+URAMP(V(G1,K)))*1.2+0.4)
BIK2  IK2  0 V=V(IK,IG)*(1-0.4*(EXP(-URAMP(V(A,K))/URAMP(V(G2,K))*15)-EXP(-15)))
BIG2T IG2T 0 V=V(IK2)*(0.75853563*(1-URAMP(V(A,K))/(URAMP(V(A,K))+10))**1.5+0.24146437)
BIK3  IK3  0 V=V(IK2)*(URAMP(V(A,K))+3175)/(URAMP(V(G2,K))+3175)
BIK4  IK4  0 V=V(IK3)-URAMP(V(IK3)-(0.001722887*(URAMP(V(A,K))+URAMP(URAMP(V(G2,K))-URAMP(V(A,K))))**1.5))
BIP   IP   0 V=URAMP(V(IK4,IG2T)-URAMP(V(IK4,IG2T)-(0.001722887*URAMP(V(A,K))**1.5)))
BIAK  A    K I=V(IP)+1e-10*V(A,K)
BIG2  G2   K I=URAMP(V(IK4,IP))
BIGK  G1   K I=V(IG)
* CAPS
CGA   G1  A  0.03p
CGK   G1  K  7.2p
C12   G1  G2 4.8p
CAK   A   K  2.8p
.ENDS