The resolution of precision mechatronic systems is fundamentally limited by the the noise and distortion performance of digital-to-analog converters. The sources of noise and distortion include quantization error, non-linearity, thermal noise, and semiconductor noise. In precision control applications, the primary limitation is harmonic distortion due to quantization and element mismatch. In this article, quantization noise and harmonic distortion are reduced by combinations of small noise dithers and large high-frequency periodic dithers. Theoretical predictions are confirmed experimentally on a closed-loop nanopositioning system. The results show reasonable correspondence to simulation and a significant reduction in noise due to quantization and element mismatch.