It makes sense comparing Yamaha RX-V677 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 RX-V677 has such a W/Ohm ratio - 90/8, 150/4 when TX-RZ710 has a power of 175/6. The THD is 0.09% for the RX-V677 but 0.08% for the TX-RZ710.
Characteristics of digital to analog converter (DAC) are different, Burr-Brown 192 KHz/24-bit for RX-V677 and AK4458 384 KHz/32-bit for the TX-RZ710. Both the RX-V677 and the TX-RZ710 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. Spotify can be used on each receiver. The RX-V677 can work with the audio stream from Pandora, Napster, JUKE, and the TX-RZ710 can receive a content from Deezer, TIDAL, Pandora, Tunein Radio.
Only the Onkyo TX-RZ710 has support for High dynamic range (HDR). 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. Both rivals can scale the resolution of the incoming HDMI signal. The HDR standard - Dolby Vision is not supported by these receivers.
The Yamaha RX-V677 has 6/1 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. The TX-RZ710 has 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. It is also worth noting that the ECO mode is presented in each of the receivers. The setup assistant will help you configure Yamaha RX-V677.
Only the TX-RZ710 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the TX-RZ710.