SPICE PARAMETERS

Spice Parameters are used in simulation software. The most used software is LTspice, a SPICE-based analog electronic circuit simulator computer software, produced by semiconductor manufacturer Analog Devices. It is the most widely distributed and used SPICE software in the industry. Though it is freeware, LTspice is not artificially restricted to limit its capabilities. For a newcomer, Spice is not self explaining, so you do need to follow some of the internet tutorials, but once you understand how it works, you will be surprized about what it can do. The limitation is only, you do not have the required S-Parameters for every part you want to use. You find many though in the internet. Simple parameters you can do yourself, like a C, R or L. If not existing, there are ways to extract the S-Parameters from the tube charts. There are many help websites and forums for this, and many enthusiasts. Read more about this.

We have at this moment only S parameters for the12B. If somebody has made good parameters for the other tubes, we would be glad to place it here.
12B tube:

* Created on Wed Jan 29 22:05:04 CET 2020 using tube.model.finder.PaintKIT
.SUBCKT EML_12B 1 2 3 ; P G K ;
+ PARAMS: CCG=13.5P  CGP=12P CCP=8P RGI=2000
+ MU=14.616 EX=1.565 KG1=2250.0 KP=300.0 KVB=500.0 VCT=-0.1 ; Vp_MAX=700.0 Ip_MAX=0.1 Vg_step=3.5
E1 7 0 VALUE={V(1,3)/KP*LOG(1+EXP(KP*(1/MU+(V(2,3)+VCT)/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

Spice is based on a "network and node" system, in which each component used, has "nodes", which are it's connections. Nodes are connected by wires. The program will calculate for each element what comes out, by looking at what goes in (what nodes is it connected to) and by the transfer function it is calculated what comes out. This breaks down a complex schematic, do the signals on the nodes only. So without having to understand how the circuit works. Like every resistor in whatever circuit has always a known current at every moment with a known voltage. In Spice, this is done, by splitting a second in many small steps, and for each step this is done separately for all nodes in the network

The beginning of a simulation is always, to build the schematic in LTspice software. These schematics look good, and they always look the same. You will immediately recognise the "looks" of a schematic, made with LTspice.

When done with the schematic, you need to set up the simulation, like choose the input signal, from a virtual signal source, etc. Then run it, and after that, with virtual voltmeters and virtual amperemeters, you can touch any wire of the schematic, to see the waveshape, like on the bench with an oscilloscope. When doing so for the first time, build something simple like an RC low pass filter, and see how that works and how it's done. You can also attach a variable frequency to the input of course. Then try it with a diode or a triode, etc. You can also download some complete tube circuits, from sites like Duncan amps. But even though these circuits are "ready to use", you do need to set it up right. So there is no way to skip the basics. Yet when you see for instance a Push Pull EL34 amplifier working for the first time in LTspice, it will sure amazy you totally, and inspire you. Such am LTspice schematic is on the Duncan Amps site. Also some great freeware like PSU designer is written with spice. However this is a higher level of programming, it uses a run-time environment. This is more difficult to program, but it can be used by anybody, without having to understand Spice, or even knowing what that is.

Some good Links for SPICE PARAMETERS

=> Free Download of Spice Simulator Program. Download only the original from Analog Devices .

http://www.dmitrynizh.com/

Duncan Amps

Youspice.com

Random links about Spice Paramaters