The Marantz SD820 is a high-end Blu-ray Disc player that was introduced by Marantz in 2011. It is designed to deliver top-of-the-line video and audio performance, with features such as Ultra HD upscaling, THX SelectPlus certification, and audiophile-grade Burr-Brown digital-to-analog converters. Additionally, it supports a range of AV technologies, including 3D Blu-ray, 4K upscaling, and HDMI CEC connectivity. Overall, the Marantz SD820 is a premium choice for audiophiles and home theater enthusiasts seeking exceptional performance and features.