Having had an opportunity to test Marantz AV8805 vs Yamaha RX-S602, I’d like to share my impression here to facilitate your choice of a new AV receiver.
The number of channels for receivers is different - 13.2 versus 5.1, respectively, for devices. A common feature for devices is the same total harmonic distortion - 0.08%.
The manufacturer installed different DACs, the AV8805 received the model AK4490 384 KHz/32-bit, but the RX-S602 is equipped with Burr-Brown 384 KHz/32-bit. Each of the compared opponents supports Bi-amping. Both Marantz AV8805 and Yamaha RX-S602 can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Each of the receivers has a Bluetooth connector. Both devices can work with such Apple Music services: AirPlay, AirPlay 2. Access to the Spotify service is on each of the competitors. The number of available streaming services varies for receivers, the Marantz AV8805 works with Deezer, TIDAL, Pandora, SiriusXM, TuneIn Radio, but the Yamaha RX-S602 works with Deezer, TIDAL, Pandora, Napster, SiriusXM, Qobuz. The quality of 4K/60Hz signal remains unchanged when transmitting from a source to a TV or projector via HDMI for both receivers. Signaling over HDMI in standby mode can provide the AV8805 and the RX-S602. Video scaling is only possible with the AV8805. Operation with the Dolby Vision is only possible with the AV8805.
The number of HDMI inputs/outputs varies depending on the receiver, the AV8805 has 8/3, and the RX-S602 has 4/1. HDMI Audio Return Channel is implemented in both devices. HDMI eARC is only supported by the AV8805. When comparing receivers, it becomes clear that each of the rivals can work with HDMI CEC. The AV8805 has support for the standard HDCP 2.2, compared to the RX-S602, which supports the standard HDCP 2.3. In the presence of a built-in phono stage for connecting a vinyl player only at Marantz AV8805.
Unlike the AV8805 where 3 Multi zones is provided, the RX-S602 works with 2 Multi zones. For voice control in the AV8805 is used Amazon Alexa, Google Assistant, Siri, Josh.AI, but in the RX-S602 is used Amazon Alexa, Google Assistant. There is an ECO mode in either AV receiver. The Marantz AV8805 and the Yamaha RX-S602 can be properly configured using the setup assistant.
A Dolby Atmos multichannel audio format is available only in the AV8805. Only in the AV8805 realized a DTS:X surround technology.