Abstract: A main feedback system regulates an output parameter of interest, such as velocity, versus a given range of load parameters, such as torque and inertia. An element feedback system rapidly adjusts an in-series-path zero to frequency track (cancel) a varying load-caused pole--including in-range variations of 100:1. Since zero-setting is inverse to an adjusted resistance required, a 100:1 zero range causes a highly non-linear resistance transmission, affecting the element loop's gain but not that of the main control feedback loop. By introducing a variable resistance of the same value as used in the main feedback system as a divider in the element feedback loop only, the element loop gain is made substantially constant over the entire pole-tracking range, and the element loop's bandwidth is made substantially constant over the same range, and thus rendering the dynamic response substantially constant over the same range.