This is my ultimate linear amplifier before I switch to class abD. I wanted it to be simplest possible with less than 10° phase shift at 20khz in open loop, class AB but no crossover distortion, double zero in THD. I came up with this circuit, 2 stage MOSFET amplifier. It has 125khz open loop bandwidth with 55db loop gain.
I simulated with Tina and Ltspice with in built models for Tina and Cordell models with Ltspice. In both I have same response but different adjustments. Both models get crossover cleaned at 200ma bias without degenerating sources. As the graph shows it has zero PM, idem in Tina. As this is transconductance output, the gain increases by current by over 6 folds, this makes the graph meaningless. This why I worked by square wave transients as it reflects better the stability at different output currents. And the transients are excellent despite the must oscillating feedback.
On Tina I show the transient of 15Vp 10khz start without input RC, if any oscillation exist, it shows clearly, and there is non. How this is possible? again an illusion?