Having had an opportunity to test Sony STR-ZA810ES 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 - 7.2 versus 5.1, respectively, for devices. In terms of power, there are differences, the STR-ZA810ES has such a ratio W/Ohm - 100/8, while the RX-S602 has a power of 80/8, 125/6. The value of total harmonic distortion is also different, and for the STR-ZA810ES it is 0.09%, but for the RX-S602 it is 0.08%.
The manufacturer installed different DACs, the STR-ZA810ES received the model 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 Sony STR-ZA810ES 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. The contenders have differences in the supported services from Apple - AirPlay versus AirPlay, AirPlay 2 respectively. Access to the Spotify service is on each of the competitors.
The HDR10 function is present in each of the rivals. 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 STR-ZA810ES and the RX-S602. Video scaling is only possible with the STR-ZA810ES. Operation with the Dolby Vision is only possible with the STR-ZA810ES.
The number of HDMI inputs/outputs varies depending on the receiver, the STR-ZA810ES has 6/2, and the RX-S602 has 4/1. HDMI Audio Return Channel is implemented in both devices. HDMI eARC is only supported by the STR-ZA810ES. When comparing receivers, it becomes clear that each of the rivals can work with HDMI CEC. The STR-ZA810ES has support for the standard HDCP 2.2, compared to the RX-S602, which supports the standard HDCP 2.3. Unlike most receivers, our models do not have a built-in phono stage for connecting a vinyl player.
Ability to create 2 Multi zones inherent in both AV receivers. For voice control in the STR-ZA810ES is used Google Assistant, but in the RX-S602 is used Amazon Alexa, Google Assistant. There is an ECO mode in RX-S602. The Sony STR-ZA810ES and the Yamaha RX-S602 can be properly configured using the setup assistant.
A Dolby Atmos multichannel audio format is available only in the STR-ZA810ES. Only in the STR-ZA810ES realized a DTS:X surround technology.