Physics-based control of virtual characters traditionally uses high simulation frequencies of 1 to 2 kHz. While lowering the simulation frequency frees computation time, it usually introduces instabilities within the simulation. In this paper, we propose a control strategy that can be used for high and low simulation frequencies, down to 225 Hz. The inherent instabilities were reduced by optimizing control parameters and by introducing a novel control feedback for the stance leg. We also show how lower frequencies hold a more restrictive space of possible control parameters than higher ones. Our controller shows equal robustness as high frequency controllers while requiring in average only 0.8 ms per simulation step.