Hi Jan
You asked me what the contact voltage is.
This is a voltage caused by different materials used for different electrodes. It is typically 0.55V or so, for sure less than a volt.
It offsets the triode's Plate current curves, in same manner as there would be a voltage source connected between the grid pin and the actual grid.
To get your measurement fitted, I had to tune the contact voltage to a very unusual high value. So I suppose there's something wrong...
BR Adrian
PS: I will send you the (most probably not accurate due to this issue) spice model code in a private message, ok?
You asked me what the contact voltage is.
This is a voltage caused by different materials used for different electrodes. It is typically 0.55V or so, for sure less than a volt.
It offsets the triode's Plate current curves, in same manner as there would be a voltage source connected between the grid pin and the actual grid.
To get your measurement fitted, I had to tune the contact voltage to a very unusual high value. So I suppose there's something wrong...
BR Adrian
PS: I will send you the (most probably not accurate due to this issue) spice model code in a private message, ok?
I have got intrigued by using triode part of EM84 for audio purposes to see how it behaves. I cannot find EM84 plate characteristic, datasheets show just length of column plotted depending on grid voltage. I am aware there are commercial devices but I do not want to invest into them. It surely could be possible to do it old fashioned way as in the fundamental course p.44.
In order to spare myself the effort I was wondering if someone already made the measurements or better yet has the model available to share.
In order to spare myself the effort I was wondering if someone already made the measurements or better yet has the model available to share.
6G2P SPICE Model
Code:
**** 6G2P ******************************************
* Created on 03/02/2024 20:18 using paint_kit.jar 3.1
* www.dmitrynizh.com/tubeparams_image.htm
* Plate Curves image file:
* Data source link:
*----------------------------------------------------------------------------------
.SUBCKT 6G2P 1 2 3 ; Plate Grid Cathode
+ PARAMS: CCG=4.2P CGP=2P CCP=3.4P RGI=2000
+ MU=95.8 KG1=2179.33 KP=676 KVB=439.29 VCT=0.424 EX=1.355
* Vp_MAX=400 Ip_MAX=5 Vg_step=0.5 Vg_start=0 Vg_count=8
* Rp=9560 Vg_ac=54.45 P_max=0.5 Vg_qui=-72.48 Vp_qui=300
* X_MIN=63 Y_MIN=187 X_SIZE=757 Y_SIZE=376 FSZ_X=1260 FSZ_Y=630 XYGrid=true
* showLoadLine=n showIp=y isDHT=n isPP=n isAsymPP=n showDissipLimit=y
* showIg1=n gridLevel2=n isInputSnapped=n
* XYProjections=n harmonicPlot=n dissipPlot=n
*----------------------------------------------------------------------------------
E1 7 0 VALUE={V(1,3)/KP*LOG(1+EXP(KP*(1/MU+(VCT+V(2,3))/SQRT(KVB+V(1,3)*V(1,3)))))}
RE1 7 0 1G ; TO AVOID FLOATING NODES
G1 1 3 VALUE={(PWR(V(7),EX)+PWRS(V(7),EX))/KG1}
RCP 1 3 1G ; TO AVOID FLOATING NODES
C1 2 3 {CCG} ; CATHODE-GRID
C2 2 1 {CGP} ; GRID=PLATE
C3 1 3 {CCP} ; CATHODE-PLATE
D3 5 3 DX ; POSITIVE GRID CURRENT
R1 2 5 {RGI} ; POSITIVE GRID CURRENT
.MODEL DX D(IS=1N RS=1 CJO=10PF TT=1N)
.ENDS
Last edited:
Might any wiser people than i, be willing to coax a model out of the curves for the 6J2P / 6Zh2P / 6Ж2П?
https://retrostore.eu/files/eshop/download/6j2p-ev_data.pdf
https://frank.pocnet.net/sheets/112/6/6Z2PEV.pdf
https://retrostore.eu/files/eshop/download/6j2p-ev_data.pdf
https://frank.pocnet.net/sheets/112/6/6Z2PEV.pdf
@Khron, I am not the modelling expert, but here is 6Z2P aka 6AS6, I hope it helps you
*Triode 6Z2P, 6AS6 03.2024 acamus
*
.subckt 6Z2P 1 2 3
xU1 1 2 3 Triode Cak=0.035p Cga=2.5p Cgk= 4.1p Kg1=656 ex=2.95 mu=32 kp=100 kvb=50 vgc=2 Rgk=2k
.ends
*
*vacuum tube triode model
*K - cathode
*A - Anode
*G - Grid
.subckt Triode A G K
C1 A G {Cga}
C2 G K {Cgk}
B1 A K I=(pow(v(e1),ex)/kg1)*(v(e1)+abs(V(e1)))/V(e1)
C3 A K {Cak}
D1 G K DGK
B2 e1 0 V=(V(a,k)/Kp)Log(1+exp(Kp(1/mu+(v(g,k)+vgc)/sqrt(kvb+pow(V(a,k),2)))))
.model DGK D(Vfwd=0 Ron={RGK} Roff=100meg)
.ends
*Triode 6Z2P, 6AS6 03.2024 acamus
*
.subckt 6Z2P 1 2 3
xU1 1 2 3 Triode Cak=0.035p Cga=2.5p Cgk= 4.1p Kg1=656 ex=2.95 mu=32 kp=100 kvb=50 vgc=2 Rgk=2k
.ends
*
*vacuum tube triode model
*K - cathode
*A - Anode
*G - Grid
.subckt Triode A G K
C1 A G {Cga}
C2 G K {Cgk}
B1 A K I=(pow(v(e1),ex)/kg1)*(v(e1)+abs(V(e1)))/V(e1)
C3 A K {Cak}
D1 G K DGK
B2 e1 0 V=(V(a,k)/Kp)Log(1+exp(Kp(1/mu+(v(g,k)+vgc)/sqrt(kvb+pow(V(a,k),2)))))
.model DGK D(Vfwd=0 Ron={RGK} Roff=100meg)
.ends
Attachments
I have found the model here, just reposting with asy fileI have got intrigued by using triode part of EM84 for audio purposes to see how it behaves. I cannot find EM84 plate characteristic, datasheets show just length of column plotted depending on grid voltage. I am aware there are commercial devices but I do not want to invest into them. It surely could be possible to do it old fashioned way as in the fundamental course p.44.
In order to spare myself the effort I was wondering if someone already made the measurements or better yet has the model available to share.
EM84.sub
- EM84 Indicator Tube Spice Model
- Author: Zabb Csaba
- Date : 10/1/2021
- The following parameters are not modelled:
- (1) Filament and filament warmup time
- (2) Limiting values
- This model is valid for the following tubes (within max. ratings):
- 6FG6, EM85E, 6FG5 EM84 6E2 6E3P
X1 1 G K EM84x
V1 A 1 DC 0
H1 4 2 V1 54k
E1 D K Value{IF{V(4,K)>0,V(4),0}}
V2 2 K DC -3.21
G1 L1 K A K 4.36u
R1 L1 K 299k
D1 L L1 DMOD
R2 D K 1MEG
.MODEL DMOD D
.ENDS
*
.SUBCKT EM84x P G K
+ PARAMS: Mu=57.99996 Ex=1.421792 Kg1=997.5376 Kp=62.31465 Kvb=9849.735
E1 1 0 Value={V(P,K)/Kp*Log(1+Exp(Kp*(1/Mu+(V(G,K)-2.33)/Sqrt(Kvb+V(P,K)*V(P,K)))))}
G1 P K Value={(Pwr(V(1),Ex)+Pwrs(V(1),Ex))/Kg1}
Rcp 2 K 4.3MEG
D1 P 2 DMOD
Bg G K I=(URAMP(V(G,K)+5.95E-1)^1.5)*1.15E-5
.MODEL DMOD D
.Ends
*
EM84.asy
Version 4
SymbolType CELL
LINE Normal 48 -16 48 0
LINE Normal -48 -16 -48 0
LINE Normal 20 0 12 0
LINE Normal -12 0 -20 0
LINE Normal -28 0 -36 0
LINE Normal 24 12 -24 12
LINE Normal 32 48 32 20
LINE Normal 24 12 32 20
LINE Normal -24 12 -32 20
LINE Normal 28 16 -28 16
LINE Normal -15 -17 -29 -17
LINE Normal -15 -13 -29 -13
LINE Normal -15 -17 -15 -13
LINE Normal -29 -17 -29 -13
LINE Normal 16 -80 16 -48
LINE Normal 23 -48 9 -48
LINE Normal 23 -44 9 -44
LINE Normal 23 -48 23 -44
LINE Normal 9 -48 9 -44
LINE Normal 64 -32 32 -32
LINE Normal 32 -25 32 -39
LINE Normal 28 -25 28 -39
LINE Normal 32 -25 28 -25
LINE Normal 32 -39 28 -39
LINE Normal 36 0 28 0
LINE Normal 40 5 36 0
LINE Normal 40 16 28 16
LINE Normal 40 5 40 16
LINE Normal -32 -32 -32 -64
LINE Normal -22 -32 -32 -32
LINE Normal -22 -17 -22 -32
LINE Normal -48 0 -36 0
ARC Normal 48 -64 -48 32 48 -16 -48 -16
ARC Normal 48 -48 -48 48 -48 0 48 0
WINDOW 0 -8 -80 Right 2
WINDOW 3 24 64 Right 2
SYMATTR Value EM84
SYMATTR Prefix X
SYMATTR Description 6FG5 EM84 6E2 6E3P
SYMATTR ModelFile EM84.sub
SYMATTR SpiceModel EM84
PIN 16 -80 NONE 0
PINATTR PinName L
PINATTR SpiceOrder 4
PIN -48 0 NONE 0
PINATTR PinName G
PINATTR SpiceOrder 2
PIN 32 48 NONE 0
PINATTR PinName K
PINATTR SpiceOrder 1
PIN -32 -64 NONE 0
PINATTR PinName A
PINATTR SpiceOrder 3
PIN 64 -32 NONE 0
PINATTR PinName D
PINATTR SpiceOrder 5
This is great -- thanks -- works fine for SIMETRIXCourtesy of jazbo8 the Ayumi SPICE model library:
Files included, copyrighted material, if you distribute these files make sure that the first three lines are not removed.
PSpice Models => View attachment 638558
A time-saver, the file below contains all the Ayumi SPICE models that are compatible with LTspice - manual editing of the files is no longer required!
LTspice Models => View attachment 689353 (New 06/29/2018)
useful for comparing distortion of tube circuits to transistor tube emulation circuit equivalents . Grid leak effect is an important area to emulate
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