The pulse-driven AC Josephson voltage standard (ACJVS) uses high-speed pulse sequences to drive a Josephson junction array, offering advantages such as spectral purity and wide bandwidth. The programmable Josephson voltage standard (PJVS), driven by a bias current, provides higher output amplitude but lower synthesis frequencies and higher-order harmonics. This paper presents a comparison of two AC quantum voltage systems using differential sampling techniques. The experiment verifies the consistency of AC quantum voltages at 50 Hz, 62.5 Hz, and 100 Hz under 0.75 V, and assesses the impact of sampler gain, frequency response, transmission line corrections, induced voltage, and crosstalk on the results. Comparison results indicate that the consistency between the two quantum voltage systems under the conditions of 50 Hz, 62.5 Hz, and 100 Hz frequencies with RMS amplitude of 0.75 V are (0.025±0.320) μV/V, (0.005±0.124) μV/V, and (0.150±0.215) μV/V, respectively. The research provide a technical foundation for the BIPM.EM-K10 comparison recommended by the International Bureau of Weights and Measures (BIPM).