Fatal error: tube: transmission line z0 must be given


#1

Hello,

I am quite new to Kicad and ngpsice, although used spice in the 1980’s :slight_smile:
I am trying to simulate a simple vacuum tube preamp but get an error “Fatal error: tube: transmission line z0 must be given” Is this some kind of bug or do I miss something?

TUBE LIBRARY

  • This library was developed by Norman Koren.
  • For details, refer to the article, "Improved Vacuum-Tube Models
  • for SPICE simulations," Glass Audio, Vol. 8, No. 5, 1996,
  • available from Audio Amateur Corporation, 305 Union St.,
  • PO Box 176, Peterborough, NH 03458 USA. Phone 603-924-9464.
  • All the usual legal disclaimers apply. The author has made
  • every effort to provide correct information, but assumes no
  • liabilities for errors, misuse of the models,
  • or inevitable changes made by users.
  • The author welcomes your comments, stories, and questions
  • (if they don’t require too much effort to answer). For really
  • BIG stuff, he will consider consulting for a fee.
  • Please contact Norman Koren by Email at kormar@cts.com.
  • Some models are commented out because the evaluation version of
  • Pspice has a maximum of twenty.

.func LIMIT(x,a,b) {min(max(x, a), b)}
.func PWR(x,a) {abs(x) ** a}
.func PWRS(x,a) {sgn(x) * PWR(x,a)}
.func stp(x) {u(x)}

  • Comment out one of the two models below (OLD or NEW). Use OLD temporarily for article.
  • .SUBCKT 12AX7 1 2 3 ; P G C; OLD MODEL
    • PARAMS: MU=93 EX=1.5 KG1=1360 KP=10000 KVB=0 RGI=2000
    • CCG=2.3P CGP=2.4P CCP=.9P ; ADD .7PF TO ADJACENT PINS; .5 TO OTHERS.
      .SUBCKT 12AX7 1 2 3 ; P G C; NEW MODEL
  • PARAMS: MU=100 EX=1.4 KG1=1060 KP=600 KVB=300 RGI=2000
  • CCG=2.3P CGP=2.4P CCP=.9P ; ADD .7PF TO ADJACENT PINS; .5 TO OTHERS.
    E1 7 0 VALUE=
    +{V(1,3)/KPLOG(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

.title KiCad schematic
.include “C:\Tubemods\Tube12ax7.lib”
V1 In 0 dc 0 ac 0 sin(0 1 1k)
R3 NC_01 0 1000
R4 out Net-R4-Pad2 100k
XU1 out Net-C1-Pad1 NC_02 12AX7
R1 In 0 100k
V2 Net-R4-Pad2 0 dc 300 ac 0
R2 Net-C1-Pad1 In 10k
C1 Net-C1-Pad1 0 470p
.tran 1u 10m
.end


#2

Comment removed, let’s think first


#3

Is this line correct? Did you enable the params? The line has to start with a .params (dot in front!).
A bit difficult to read: better mark the i/o as preformatted text. Otherwise the text editor mangles the characters a bit.

If params without dot, it is read as a transmission line.


#4

May be it is just this first line.

Add an * in front of it.


#5

Thats it!
Added a * to Tube Library and it works
Thanks