Potential stability of DC operating points in the circuits with controlled sources

A paradox is described related to the fact that in spite of evident circuit instability due to strong positive feedback, all poles of active dynamical circuits lie in the left-side complex plane. It is shown that the key problem is the incomplete circuit model, because the pole location can strongly depend on the inclusion of parasitic reactances. This phenomenon is investigated together with the so-called potential stability of the DC operating point.