Sennheiser HDV 820 Digital Headphone Amplifier (507443) is a next-generation digital headphone amplifier designed for high-end audio enthusiasts. It features the class-leading ESS 9028PRO SABRE DAC for extremely precise and detailed sound reproduction. It performs exceptionally with digital sources via optical, coaxial, and USB connections. The amplifier includes both balanced (XLR) and unbalanced (RCA) analog inputs and perfectly complements Sennheiser audiophile headphones. It supports DSD256 (up to 12.3 MHz) and PCM formats up to 32-bit / 384 kHz. Audio outputs include XLR3, XLR4, a 6.3 mm jack, and a 4.4 mm Pentaconn connector for versatile connectivity.