EL152 Pentode Spice Model

Some time ago I got hold of a nice stash of Telefunken EL152. These German pentodes are amazing. After playing with the RL12P35P and then obviously GU-50 (which is a copy of the LS-50), the EL152 was a nice valve to have at hand as it’s actually the LS-50 in a different bottle.

The B-10V socket is quite tricky as it seems like it was designed for the EL/FL-152 and similar Telefunken valves. Anyhow, managed to get some new ceramic ones to trace the curves and generate a Spice model. Hope you find this useful.

Here’s the model using Derk’s tool:

LT Spice models

Pentode model is below and also here: EL152-pentode-model:

****************************************************
.SUBCKT EL152-pentode 1 2 3 4 ; A G2 G1 C;
*      Extract V3.000
* Model created: 23-Oct-2020
*
* Curves traced and Model developed by Alejandro Moglia
* (c) 2020 by Bartola Ltd. UK 
* For DIY Audio Use Only
* www.bartola.co.uk/valves email: valves@bartola.co.uk
*
X1 1 2 3 4 PenthodeD  MU=  5.4 EX=1.390 kG1= 707.4 KP=  32.3 kVB =  5122.1 kG2=46214.5
+ Ookg1mOokG2=.14E-02 Aokg1=.45E-06 alkg1palskg2=.14E-02 be=   .07 als= 50.58 RGI=2000
+ CCG1=10.0P  CCG2 = 0.0p CPG1 = 0.11p CG1G2 = 0.0p CCP=14.5P  ;
.ENDS

****************************************************

.SUBCKT PenthodeD 1 2 3 4; A G2 G1 C
*
* NOTE: LOG(x) is base e LOG or natural logarithm.
* For some Spice versions, e.g. MicroCap, this has to be changed to LN(x).
*
RE1  7 0  1MEG    ; DUMMY SO NODE 7 HAS 2 CONNECTIONS
E1 7 0 VALUE=
+{V(2,4)/KP*LOG(1+EXP(KP*(1/MU+V(3,4)/SQRT(KVB+V(2,4)*V(2,4)))))}
E2   8 0 VALUE = {Ookg1mOokG2 + Aokg1*V(1,4) - alkg1palskg2/(1 + be*V(1,4))}
G1   1 4  VALUE = {0.5*(PWR(V(7),EX)+PWRS(V(7),EX))*V(8)}
G2   2 4 VALUE = {0.5*(PWR(V(7),EX)+PWRS(V(7),EX))/KG2 * (1+ als/(1+be*V(1,4)))}

RCP  1 4  1G      ; FOR CONVERGENCE A  - C
C1   3 4  {CCG1}   ; CATHODE-GRID 1 C  - G1
C4   2 4  {CCG2}   ; CATHODE-GRID 2 C  - G2
C5   2 3  {CG1G2}   ; GRID 1 -GRID 2 G1  - G2
C2   1 3  {CPG1}  ; GRID 1-PLATE G1 - A
C3   1 4  {CCP}   ; CATHODE-PLATE A  - C
R1   3 5  {RGI}   ; FOR GRID CURRENT G1 - 5
D3   5 4  DX      ; FOR GRID CURRENT 5  - C
.MODEL DX D(IS=1N RS=1 CJO=10PF TT=1N)
.ENDS PenthodeD

****************************************************
.SUBCKT EL152-triode 1 2 3; A G C;
* Extract V3.000
* Model created: 23-Oct-2020
*
*
* Curves traced and Model developed by Alejandro Moglia
* (c) 2020 by Bartola Ltd. UK 
* For DIY Audio Use Only
* www.bartola.co.uk/valves email: valves@bartola.co.uk
*
X1 1 2 3 TriodeK MU= 5.43 EX=1.423 KG1= 707.4 KP= 32.3 KVB= 5122. RGI=2000
+ CCG=0.0P CGP=0.0P CCP=0.0P ;
.ENDS

****************************************************
.SUBCKT TriodeK 1 2 3; A G C
*
* NOTE: LOG(x) is base e LOG or natural logarithm.
* For some Spice versions, e.g. MicroCap, this has to be changed to LN(x).
*
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={0.5*(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 TriodeK

Author: Ale Moglia

"A mistake is always forgivable, rarely excusable and always unacceptable. " (Robert Fripp) View all posts by Ale Moglia