Having had an opportunity to test Yamaha RX-A780 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 RX-A780 has such a ratio W/Ohm - 95/8, 160/4, while the RX-S602 has a power of 80/8, 125/6. The value of total harmonic distortion is also different, and for the RX-A780 it is 0.06%, but for the RX-S602 it is 0.08%.
Competitive models use the same DAC. Each of the compared opponents supports Bi-amping. Both Yamaha RX-A780 and Yamaha RX-S602 can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
These units have the same Wi-Fi modules. 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. Most popular streaming services are available for our models under consideration - Deezer, TIDAL, Pandora, Napster, SiriusXM, Qobuz.
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 RX-A780 and the RX-S602. Video scaling is only possible with the RX-A780. Operation with the Dolby Vision is only possible with the RX-A780.
The number of HDMI inputs/outputs varies depending on the receiver, the RX-A780 has 7/2, and the RX-S602 has 4/1. HDMI Audio Return Channel is implemented in both devices. HDMI eARC is only supported by the RX-A780. When comparing receivers, it becomes clear that each of the rivals can work with HDMI CEC. RX-A780 and RX-S602 support the standard HDCP 2.3. In the presence of a built-in phono stage for connecting a vinyl player only at Yamaha RX-A780.
Ability to create 2 Multi zones inherent in both AV receivers. Voice control is performed using Amazon Alexa, Google Assistant in both models. There is an ECO mode in either AV receiver. The Yamaha RX-A780 and the Yamaha RX-S602 can be properly configured using the setup assistant.
A Dolby Atmos multichannel audio format is available only in the RX-A780. Only in the RX-A780 realized a DTS:X surround technology.