Sennheiser HDV 820 US Digital Headphones Amplifier, NOB New Opened Box Condition. Description Pair your reference-class headphones with this Sennheiser headphone amplifier. It delivers accurate, clear playback for analyzing rhythms effectively, and it offers a sampling rate up to 384kHz for high-resolution audio. This Sennheiser headphone amplifier is compatible with a variety of digital and analog sources, including XLR, RCA and USB for versatile use. Features Sennheiser HDV 820 digital headphones amplifier High-quality ESS SABRE32 digital-t