Here's a link to the Ayumi N. model for 4P1L tetrode, if that helps. I think it was created from the published data sheet curves.
http://www.diyaudio.com/forums/tubes-valves/243950-vacuum-tube-spice-models-118.html#post4752673
There are a couple of other models in there as well.
http://www.diyaudio.com/forums/tubes-valves/243950-vacuum-tube-spice-models-118.html#post4752673
There are a couple of other models in there as well.
I added interesting russian triode 6S19P. Due to its parameters (very low internal resistance etc.), it is difficult to simulate. There are slight differences of anode characteristics for very high voltages and very low anode currents. These are fortunately scopes of work, which (for this tube) are not used in audio systems. So I hope that simulations will be useful 
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.I am not sure if I understand your question but in SE common cathode amplifier configuration with independent negative bias and cathode connected directly to ground the Ua is the anode to ground and at the same time anode to cathode voltage. If you use automatic bias in the form of cathode resistor (its value is suggested in the table below the figure) you have to add the voltage on this resistor to the Ua. In the second situation Ua is the anode to cathode voltage and anode to ground is the Ua plus the bias voltage. Please correct me if my answer is unclear or I did not understand the question.
This is a neat and helpful tool. Any chance that you can make it work for the following tubes:
6ar6/6098
5336A
6as7g
6v6GT as pentode
I was also wondering if you can have it calculate for two tubes in push pull both class A and AB1, so that we can see what the expected power output will be for such arrangements?
6ar6/6098
5336A
6as7g
6v6GT as pentode
I was also wondering if you can have it calculate for two tubes in push pull both class A and AB1, so that we can see what the expected power output will be for such arrangements?
As I have said before, this is an excellent tool - I love it. It makes life so much easier in checking different operating points. Since you are working on the software, is it possible to add a few more Russian's like the very linear 4P1L and 6E5P in triode as well as the 6V6 and EL84 in pentode mode?
Thanks again for a very useful piece of software, it's much appreciated!
Dimitry Nizh triode model for 6E5P:
http://www.bartola.co.uk/valves/wp-content/uploads/2012/05/6E5P_T.txt
Ale Moglia triode model for 4P1L:
4P1L triode SPICE model – Bartola Valves
Thanks again for a very useful piece of software, it's much appreciated!
Dimitry Nizh triode model for 6E5P:
http://www.bartola.co.uk/valves/wp-content/uploads/2012/05/6E5P_T.txt
Ale Moglia triode model for 4P1L:
4P1L triode SPICE model – Bartola Valves
This problem does nor occur in my browsers and operating systems (Firefox and Chrome - Windows XP, Firefox - Windows 7/10).