• 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

I did a quick sim using this model (and the previous one) in a PP amp. I was hoping triode-wired GU15 might work as a replacement for expensive 2A3 triodes. Alas, it looks like the GU15 wired triode likes to make a lot more 3rd harmonic than the 2A3 -- or at least judging by the modeled circuits.

I tried various impedance OPT models. It seems the GU15-Triode works better into high primary impedance loads, like 10k:VC. Of course my real-life OPT collection contains only 5k and 6.6k items. I just knew I should have held onto those old UTC LS63 OPTs I sold a few years back. (Even though I did get a lot of money for them.)

At any rate, thank you very much for the model. I'll try to figure out a circuit that will work well with them, someday. But for now, working with the model kept me from going shopping for tubes I don't really need! :D
 
4D32

To make the SPICE models for the above two tubes, please provide their triode-connected characteristic curves.

I have the Raytheon datasheet for the 4D32 but it doesn't include triode-connected anode characteristics.

Google isn't being much help either. I don't have one to put on a curve tracer even if my curve tracers were capable of 1000V and 2.2A.
 

Attachments

  • 4D32.pdf
    357.9 KB · Views: 72
Ex-Moderator
Joined 2011
They are not really models, just simple schematics. All you need to do in the schematic is to sweep the voltage sources on the plate and the grid for a triode. For the pentode, you add another voltage source for the screen grid, and set the voltage per the datasheets. Before you can do that, make sure you have the correct symbol for the pentode, since many SPICE models online have their pins swapped around.
 
6829_mod.jpg

Does anyone have a SPICE model for the 6829? Although I've seen people say that the 12AT7 is about the same as the 6829, a comparison of the two tubes' plate curves doesn't bear this out.


Thanks.

Try this. I just made this quickly, but it fits reasonably well.
(See attachment.)
Code:
.SUBCKT 6829 1 2 3 ; P G C; KOREN MODEL (TRIODE) 
+ PARAMS: MU=55 EX=1.31 KG1=298.75 KP=162 KVB=550 RGI=2000 
+ CCG=5.0P CGP=3.6P CCP=.57P ; ADD .7PF TO ADJ PINS, .5 TO OTHERS. 
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
Hope this helps,

Jim
 
Does anyone have a SPICE model for the 6829? Although I've seen people say that the 12AT7 is about the same as the 6829, a comparison of the two tubes' plate curves doesn't bear this out.


Thanks.
6829=5965, except lower Vp max (275 vs 300 for 5965, 330 for 5965A) and lower Pd.


Not to take away from jelanier's post, but here's two models I just made for use in LTspice, one in Curve Captor and one using Ayumi's method... ;)


Curve Captor:
Code:
* ============================================================== 
* CK6829 LTSpice model 
* Modified Koren model (8 parameters): mean fit error 0.186067mA 
* Traced by Wayne Clay on 06/17/2018 using Engauge Digitizer and 
* Curve Captor v0.9.1 from Raytheon data sheet 
* ============================================================== 
.subckt CK6829  P G K 
    Bp  P K  I= 
+ (0.02268049449m)*uramp(V(P,K)*ln(1.0+(-0.02982574749)+exp((1.560781257)+ 
+ (1.560781257)*((66.6612651)+(-1067.129594m)*V(G,K))*V(G,K)/sqrt((40.14838418)**2+ 
+ (V(P,K)-(9.147083081))**2)))/(1.560781257))**(1.370120586) 
    Cgp G P 3.1p ; 0.7p added (2.4p) 
    Cgk G K 3.7p ; 0.7p added (3.0p) 
    Cpk P K 0.57p ; 0.2p added (0.37p) 
    Rpk P K 1G 
    d3  G K dx1 
.model dx1 d(is=1n rs=2k cjo=1pf N=1.5 tt=1n) 
 .ends CK6829
Ayumi Nakabayashi model:
Code:
*
* Generic triode model: CK6829_AN
* Copyright 2003--2008 by Ayumi Nakabayashi, All rights reserved.
* Version 3.10, Generated on Sun Jun 17 20:48:19 2018
*                 Plate
*                 | Grid
*                 | | Cathode
*                 | | |
.SUBCKT CK6829_AN A G K
BGG   GG   0 V=V(G,K)+0.17652075
BM1   M1   0 V=(0.019871805*(URAMP(V(A,K))+1e-10))**-1.5762085
BM2   M2   0 V=(0.48761325*(URAMP(V(GG)+URAMP(V(A,K))/25.784611)+1e-10))**3.0762085
BP    P    0 V=0.0047751592*(URAMP(V(GG)+URAMP(V(A,K))/52.879225)+1e-10)**1.5
BIK   IK   0 V=U(V(GG))*V(P)+(1-U(V(GG)))*0.005163113*V(M1)*V(M2)
BIG   IG   0 V=0.0023875796*URAMP(V(G,K))**1.5*(URAMP(V(G,K))/(URAMP(V(A,K))+URAMP(V(G,K)))*1.2+0.4)
BIAK  A    K I=URAMP(V(IK,IG)-URAMP(V(IK,IG)-(0.0025236727*URAMP(V(A,K))**1.5)))+1e-10*V(A,K)
BIGK  G    K I=V(IG)
* CAPS
CGA   G    A 3.1p ; 0.7p added (2.4p)
CGK   G    K 3.7p ; 0.7p added (3.0p)
CAK   A    K 0.57p ; 0.2p added (0.37p)
.ENDS
 

Attachments

  • CK6830_CC.png
    CK6830_CC.png
    40.1 KB · Views: 507
  • CK6829-Rplot.png
    CK6829-Rplot.png
    103.8 KB · Views: 520
I'm just trying to get re-started with circuit models in Spice after a crash last year.
A few of questions :

The download which people recommend, of Ayumi's models - in the file header they are all noted as year 2008. Is this correct or have they been update without the header being updated ?

is there a quick way of editing all of the .inc files to change the ^ to ** ?
Or is it just a case of going through each file and using 'find>replace' ?

I just brought in an extra file from Jazbo, of the 4P1L from this thread. I edited the active part of it into one of the existing files from Ayumi and saved as 4P1L , however the file type changed from .inc to .txt . Can anyone remind me how to correct the file type/extension in Windows (7 ) ?

Thanks in advance.
- and thanks for all the great work here to create and update models.
 
Last edited: