HD 820 Over-the-Ear Audiophile Headphones. Delivers impressive spatial sound reproduction. 56mm Ring Radiator dynamic transducer system. Adjustable metal headband with inner damping element. HDV 820 Digital Headphones Amplifier. Class-leading ESS SABRE digital-to-analog converter. DSD256 files up to 12.3MHz PCM files up to 32-bit and 384kHz sample rate. Audio outputs: XLR3 XLR4 6.3mm jack socket and 4.4mm Pentaconn socket. Bundle comes with Power cable 1/4" stereo jack cable and 4.4mm Stereo jack plug.