I am struggling a little with this schematic, something is wrong with the schematic (or the model) below and I cant figure out what.

When I increase the R10 using the res variable, as R10 increases, the quotient current starts dropping, not a little but a lot. With values of R10 = 10R - 15ma; 250R - 7ma; 470R - 4.8ma, 1k - 2.7ma. Of course due to this, the distortion numbers also go worse as R10 rises. Vgk rises correctly though as R10 rises.

The current calculations also don't look correct, with 3.3k and 105v supply, I should get about 31ma, but I get half of that, about 15ma. It looks like R13 is not controlling the current, but R10 is. Reducing R13 drastically doesn't seem to increase the current in proportion, R10 = 470 and R13 = 1k gives about 5ma of current.

The tube model is the ayumi model, I took it from this link (second last post) - http://www.diyaudio.com/forums/tubes-valves/243950-vacuum-tube-spice-models-40.html#post3863379

When I increase the R10 using the res variable, as R10 increases, the quotient current starts dropping, not a little but a lot. With values of R10 = 10R - 15ma; 250R - 7ma; 470R - 4.8ma, 1k - 2.7ma. Of course due to this, the distortion numbers also go worse as R10 rises. Vgk rises correctly though as R10 rises.

The current calculations also don't look correct, with 3.3k and 105v supply, I should get about 31ma, but I get half of that, about 15ma. It looks like R13 is not controlling the current, but R10 is. Reducing R13 drastically doesn't seem to increase the current in proportion, R10 = 470 and R13 = 1k gives about 5ma of current.

The tube model is the ayumi model, I took it from this link (second last post) - http://www.diyaudio.com/forums/tubes-valves/243950-vacuum-tube-spice-models-40.html#post3863379

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