Denon SPK618 HDMI 2.1 Adapter for Denon Marantz AVRs, 8K/60hz & 4K/120hz + Cable | eBay
Report: latest AVRs from Sony, Denon / Marantz, Yamaha, etc. have a bug in the HDMI 2.1 chip - unable to pass through the 4k120hz HDR10 signal (german article) : r/xboxone
Denon & Marantz Announce HDMI 2.1 Receivers 4k/120Hz Works Without Issue! | Audioholics
SOUND UNITED ANNOUNCES HDMI 2.1 8K UPGRADES TO FLAGSHIP AV COMPONENTS FROM DENON AND MARANTZ - HomeTheaterHifi.com
Denon and Marantz AV Receivers HDMI 2.1 Bug Permanently Fixed
Denon and Marantz will add HDMI 2.1 to these older receivers for $600 | Engadget
HDMI 2.1 adaptor brings three 4K 120Hz HDMI ports to latest Denon and Marantz AVRs | StereoNET Australia | Hi-Fi news and reviews