Onkyo TX-NR797 vs Yamaha RX-V4A comparison definitely makes sense.
A significant difference between the receivers in the number of channels, Onkyo TX-NR797 has 9.2 versus 5.2 for Yamaha RX-V4A. Regarding power, then TX-NR797 has such a W/Ohm ratio - 100/8, 220/6 when RX-V4A has a power of 80/6. The THD is 0.08% for the TX-NR797 but 0.06% for the RX-V4A. Both the TX-NR797 and the RX-V4A support Bi-amping. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Rivals from our review have Bluetooth support. The Apple Music service is implemented on considered devices: AirPlay, AirPlay 2. Spotify can be used on each receiver. The TX-NR797 can work with the audio stream from Deezer, TIDAL, Pandora, TuneIn Radio, and the RX-V4A can receive a content from Deezer, TIDAL, Pandora, SiriusXM, Qobuz.
Both AV receivers support HDR10 technology (High dynamic range). HDMI signal transmission in standby mode is implemented in each of the devices. Both rivals can scale the resolution of the incoming HDMI signal. The HDR standard - Dolby Vision is supported by these receivers.
The Onkyo TX-NR797 has 7/2 HDMI inputs/outputs versus 4/1 HDMI connectors of the Yamaha RX-V4A. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the RX-V4A. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. The TX-NR797 supports the protection of digital content of the standard HDCP 2.2, versus HDCP 2.3 in the RX-V4A. The TX-NR797 has a built-in phono stage for connecting a vinyl player. The TX-NR797 supports voice control via Google Assistant, and the RX-V4A - Amazon Alexa, Google Assistant, Siri. An ECO mode is only available for the RX-V4A. Both TX-NR797 and RX-V4A can be configured using the Setup assistant.
Only the TX-NR797 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the TX-NR797.