This document describes an improved high-efficiency DC-DC converter for low-voltage photovoltaic energy sources. The proposed converter uses a dual active clamping circuit and resonant voltage doubler rectifier to achieve high voltage gain and reduce voltage stress on the switches. Simulation results show the converter can achieve 98% efficiency when converting a 41V input to a 330W, 409V output. Key advantages of the proposed converter include reduced switching losses through zero-current switching of the output diodes and lower voltage stress on the switches compared to previous converter designs.