This study discusses realization possibilities of the buck mode in the novel magnetically integrated quasi-Z-Source Series Resonant Converter (qZSSRC) with secondary resonance. Our aim was to achieve higher power conversion efficiency at different power levels and DC voltage gains of the converter. The phase-shift modulation was comprehensively compared with the asymmetrical pulse width modulation. Both control techniques were evaluated for the case of the discontinuous current through the resonant network, which made their realization more challenging. The operating principle of the qZSSRC in the buck mode with two compared control techniques was explained by means of steady-state analysis. To verify the theoretical assumptions, a 250 W prototype of the PV module integrated converter was assembled and tested. It was experimentally confirmed that in contrast to the phase-shift modulation, the asymmetrical pulse width modulation for the buck mode control of the qZSSRC will lead to higher power conversion efficiency at different power levels and DC voltage gains of the converter, except the operating points close to the boundary with the normal mode of the converter.