• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Got my tube spice models, and tubed CD player page back on the air

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Lean to the right

I am trying to better understand the curves of a triode as they
might be emulated (from a vacuum diode reference to keep it
at least somewhat relevant).

Easy enough to fake any particular Mu by subtracting working
voltage from the plate (probably by action of a blocking cascode)
and thereby impress virtual copies of the diode curve at regular
Mu voltage spacings (per virtual grid volt).

What I don't get is how to lean my emulated triode curves over
to the right as the grid voltage increases?... Or scrunch them
together as the Cathode-Plate current goes down... Or spread
them apart as Cathode-Plate current goes up. Is there some
better way of looking at it that approximates the same effect?

I may be nitpicking here, but I don't want a perfect Mu, I want it
to be imperfect just like a real Triode (only without a real Triode).

SmokingAmp suggested that the lower Mu parts of a real Triode
pinch off last, and those we see at the far right. I have tried to
aproximating this my paralleling two virtual Triodes of different
Mu's. But they always add to parallel curves that do not lean...
Or something is way wrong with my math...

I am also looking at a lot of real Triode curves and do not see
the magic X^1.5 curve law followed too religiously. I see all
sorts of exponents from ^1.24 to ^1.8 in your spice models
seems to agree that ^1.5 is not an immutable law of hollow
state physics to be blindly applied in all situations.

The cascodes in this drawing probably got to be Darlingtons.
And I am not sure I have achieved any lean to the right by
paralleling different virtual Mu's...

I am using LTSpice/SWCadIII, but I have no idea how to do
anything with it yet, other than draw...

KD5ZXG
 

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