The increasing penetration of power electronic converters has given rise to emerging stability phenomena requiring new approaches to stability assessment. While electromagnetic transient simulations reveal unstable behaviour, impedance-based analysis provides further insight into the underlying causes of converter–grid interactions. Accordingly, this paper investigates how converter-level outer-loop control modes influence the small-signal stability of a grid-following voltage-source-converter-based power park connected to a weak grid. A generic 120 MW power park without a centralised park controller is implemented in PSCAD, with all outer-loop control objectives implemented locally. Particular focus is placed on comparing reactive power control and AC voltage control on the q-axis, and on evaluating DC-link voltage dynamics. Converter self- and transfer admittances are extracted using a frequency scan and combined with an analytically represented grid impedance to form the converter-grid loop gain. Stability is assessed using Bode and Nyquist analysis. The results show that outer-loop control significantly influences damping characteristics and resonance frequencies. In particular, AC voltage control introduces asymmetric damping around the fundamental frequency, giving rise to supersynchronous interactions. DC-link voltage control affects the converter impedance mainly below twice the fundamental frequency. The findings show that outer-loop control should be explicitly considered in grid-connection studies of converter-connected devices.