The Yamaha RX-V4A vs Onkyo TX-NR797 comparison proves that these receivers have many common features.
A significant difference between the receivers in the number of channels, Yamaha RX-V4A has 5.2 versus 9.2 for Onkyo TX-NR797. Regarding power, then RX-V4A has such a W/Ohm ratio - 80/6 when TX-NR797 has a power of 100/8, 220/6. The THD is 0.06% for the RX-V4A but 0.08% for the TX-NR797. Both the RX-V4A and the TX-NR797 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 RX-V4A can work with the audio stream from Deezer, TIDAL, Pandora, SiriusXM, Qobuz, and the TX-NR797 can receive a content from Deezer, TIDAL, Pandora, TuneIn Radio.
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 Yamaha RX-V4A has 4/1 HDMI inputs/outputs versus 7/2 HDMI connectors of the Onkyo TX-NR797. 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 RX-V4A supports the protection of digital content of the standard HDCP 2.3, versus HDCP 2.2 in the TX-NR797. The TX-NR797 has a built-in phono stage for connecting a vinyl player. The RX-V4A supports voice control via Amazon Alexa, Google Assistant, Siri, and the TX-NR797 - Google Assistant. An ECO mode is only available for the RX-V4A. Both RX-V4A and TX-NR797 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.