Hello,
Sorry for the noob question but I am starting to learn TINA to simulate some tube phono stages. TINA supplies some PSPICE models for standard triodes but they seem to have been simplified with constants and not tube parameters (I.e. Rp, transconductance, mu, etc.)
Is anyone familiar with these models? All I really need to do right now is modify the 12AX7 model to have it simulate a 5751. I am assuming the "95.43" is the mu? I can edit the Cgk, Cgp and Cpk as required but the big question is what about Rp as that will affect the Passive RIAA filter?
Here is the model from TINA:
.SUBCKT 12AX7A P G K
E1 2 0 VALUE={45+V(P,K)+95.43*V(G,K)}
R1 2 0 1.0K
Gp P K VALUE={1.147E-6*(PWR(V(2),1.5)+PWRS(V(2),1.5))/2}
Cgk G K 1.6P
Cgp G P 1.7P
Cpk P K 0.46P
.ENDS 12AX7A
Sorry for the noob question but I am starting to learn TINA to simulate some tube phono stages. TINA supplies some PSPICE models for standard triodes but they seem to have been simplified with constants and not tube parameters (I.e. Rp, transconductance, mu, etc.)
Is anyone familiar with these models? All I really need to do right now is modify the 12AX7 model to have it simulate a 5751. I am assuming the "95.43" is the mu? I can edit the Cgk, Cgp and Cpk as required but the big question is what about Rp as that will affect the Passive RIAA filter?
Here is the model from TINA:
.SUBCKT 12AX7A P G K
E1 2 0 VALUE={45+V(P,K)+95.43*V(G,K)}
R1 2 0 1.0K
Gp P K VALUE={1.147E-6*(PWR(V(2),1.5)+PWRS(V(2),1.5))/2}
Cgk G K 1.6P
Cgp G P 1.7P
Cpk P K 0.46P
.ENDS 12AX7A
The build-out resistor is in series w the output impedance of the driving stage.
12ax7 is high rp and not well suited to passive equalization.
I already have the phono stage but need lower gain. I am trying to simulate 5751's in the 12AX7 location to see how I need to change my RIAA components due to the different tube characteristics.
build-out resistor should be ~10x the value of rp (as rp will changes over time). for a tube with high rp (58k for the 5751) a 580k resistor will bring with it ~100nV/RtHz noise.
from the value of buildout resistor (r1 in lipshitz transform), r2=6.88 x r1, c1=318uSec/r2, c2=c1/2.92
from the value of buildout resistor (r1 in lipshitz transform), r2=6.88 x r1, c1=318uSec/r2, c2=c1/2.92
Anyone else?
Questions:
1. Can I just reduce the series resistor coming off the plate to simulate the reduced Rp?
2. Am I correct in my mu assumption in the formula?
Questions:
1. Can I just reduce the series resistor coming off the plate to simulate the reduced Rp?
2. Am I correct in my mu assumption in the formula?
5751 TINA Spice Model
Code:
*
* Generic triode model: 5751_AN
* Copyright 2003--2008 by Ayumi Nakabayashi, All rights reserved.
* Version 3.10, Generated on Sun Dec 17 16:41:13 2017
* Anode
* | Grid
* | | Cathode
* | | |
.SUBCKT 5751_AN A G K
.PARAM X1=-0.044770209 X2=0.032175849 X3=-2.2476294
.PARAM X4=0.40025303 X5=18.639663 X6=3.7476294
.PARAM X7=0.0040093865 X8=46.569699 X9=0.0099503146
.PARAM Y1=0.0020046932 Y2=0.0021345255
BK IK 0 V=U(V(G,K)+X1)*X7*URAMP(V(G,K)+X1+URAMP(V(A,K))/X8)^1.5+(1-U(V(G,K)+X1))*X9*(X2*URAMP(V(A,K)))^X3*(X4*URAMP(V(G,K)+X1+URAMP(V(A,K))/X5))^X6
BA A K I=URAMP((Y2*URAMP(V(A,K))^1.5)-URAMP((Y2*URAMP(V(A,K))^1.5)-V(IK)+Y1*URAMP(V(G,K))^1.5*(URAMP(V(G,K))/(URAMP(V(A,K))+URAMP(V(G,K)))*1.2+.4)))+1E-10*V(A,K)
BG G K I=Y1*URAMP(V(G,K))^1.5*(URAMP(V(G,K))/(URAMP(V(A,K))+URAMP(V(G,K)))*1.2+.4)
* CAPS
CGA G A 1.4p
CGK G K 1.4p
CAK A K 0.5p
.ENDS
- Status
- Not open for further replies.