The AVR-5800 is without question the most advanced and best-sounding AVR on the market. With every known form of surround sound decoding, seven amplifier channels, plenty of power, and a generous connectivity complement, the AVR-5800 can serve as the center-piece of even the most sophisticated home theater. An upgrade kit will be available from Denon beginning in April of 2002. The kit adds THX Ultra 2 processing, Lucasfilm Home THX Cinema 6.1ES post-processing, and other improvements to the AVR-5800's already formidable array of features. The kit retails at $800.