spice distortion dynamics of tube power amps

[hpupo]

Hello

Has anyone tried to use spice for simulate the full power dynamics of a PP pentode?
I have what i believe to be pretty good models (curves match data sheet, as much as possible) but i am getting strange results when i overdrive it...

Thanks

 

[bill_a]

The problem is not Spice. Overdrive, by definition, is pushing a device, tube or otherwise, into it's non-linear region. Its just like trying to simulate a real transformer - its really difficult to accurately incorporate both linear and non-linear behaviour in the same model.
All the tube models I've seen, created and used are really good if they do a half-way decent job in the "linear" region, let alone in the saturation/cut-off region.
B.

 

[hpupo]

After doing some more tests, i realized i had the "transformer" model a little wrong... i am getting something more "normal" now. At least as normal for my tests....