This article presents an advanced observer-based critical damping active disturbance rejection control (ADRC) technique for servo drive positioning applications that leverages the pole-zero cancellation (PZC) property to reduce the system model dependence. Unlike the conventional ADRC technique, the proposed technique offers two major contributions: (a) a model-free observer to extract the speed information from a discontinuous position measurement, ensuring diagonalized estimation error dynamics, and (b) the incorporation of integral action into the ADRC loop, preserving the desired critically damped closed-loop behavior via PZC. The experimental study confirms the closed-loop improvements of the proposed technique via a 500-W servo drive and compares it with that of the conventional ADRC technique.