It makes sense comparing Onkyo TX-NR777 vs Onkyo TX-RZ710 because they both are able to give some premium features.
Considered AV receivers have the same number of channels 7.2. Regarding power, then TX-NR777 has such a W/Ohm ratio - 110/8 when TX-RZ710 has a power of 175/6. The THD is the same and is 0.08%.
Characteristics of digital to analog converter (DAC) are different, 384 KHz/32-bit for TX-NR777 and AK4458 384 KHz/32-bit for the TX-RZ710. Both the TX-NR777 and the TX-RZ710 support Bi-amping. The Onkyo TX-RZ710 can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
WI-FI modules have the same characteristics: 2.4/5GHz. Rivals from our review have Bluetooth support. The Apple Music service is implemented on considered devices: AirPlay. Spotify can be used on each receiver. The TX-NR777 can work with the audio stream from TIDAL, Pandora, and the TX-RZ710 can receive a content from Deezer, TIDAL, Pandora, Tunein Radio. Compared AV receivers retain the quality of 4K/60Hz signal when transmitting from a source to a TV or projector. HDMI signal transmission in standby mode is implemented in each of the devices. The TX-RZ710 can scale the input HDMI signal, unlike the TX-NR777. Dolby Vision technology found support only on the TX-NR777.
The Onkyo TX-NR777 has 7/2 HDMI inputs/outputs versus 8/2 HDMI connectors of the Onkyo TX-RZ710. The HDMI Audio Return Channel (ARC) feature supports both devices. Unfortunately, HDMI eARC is not available on monitored devices. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. Both models support the standard HDCP 2.2. These compared receivers have a built-in phono stage for connecting a vinyl player.
Each of the AV receivers from our review supports 2 Multi-room zones. A voice control is not available. An ECO mode is only available for the TX-RZ710. The setup assistant will help you configure Onkyo TX-NR777.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review.