It makes sense comparing Yamaha AVENTAGE RX-A1080 vs Onkyo TX-RZ630 because they both are able to give some premium features.
A significant difference between the receivers in the number of channels, Yamaha AVENTAGE RX-A1080 has 7.2 versus 9.2 for Onkyo TX-RZ630. Regarding power, then AVENTAGE RX-A1080 has such a W/Ohm ratio - 110/8, 170/4 when TX-RZ630 has a power of 90/8, 215/6. The THD is 0.06% for the AVENTAGE RX-A1080 but 0.08% for the TX-RZ630.
Characteristics of digital to analog converter (DAC) are different, ESS SABRE 384 KHz/32-bit for AVENTAGE RX-A1080 and AK4458 384 KHz/32-bit for the TX-RZ630. Both the AVENTAGE RX-A1080 and the TX-RZ630 support Bi-amping. Each of the AV receivers 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 Yamaha AVENTAGE RX-A1080 has support for AirPlay, AirPlay 2, and its competitor in our comparison - AirPlay. Spotify can be used on each receiver. The AVENTAGE RX-A1080 can work with the audio stream from Deezer, TIDAL, Pandora, Sirius XM, Napster, Qobuz, and the TX-RZ630 can receive a content from Deezer, TIDAL, Pandora.
Both AV receivers support HDR10 technology (High dynamic range). 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 AVENTAGE RX-A1080 can scale the input HDMI signal, unlike the TX-RZ630. The HDR standard - Dolby Vision is supported by these receivers.
The Yamaha AVENTAGE RX-A1080 has 8/3 HDMI inputs/outputs versus 7/2 HDMI connectors of the Onkyo TX-RZ630. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the AVENTAGE RX-A1080. 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.
The AVENTAGE RX-A1080 supports 2 Multi-room zones, versus 3 for the TX-RZ630. The AVENTAGE RX-A1080 supports voice control via Amazon Alexa, Google Assistant, and the TX-RZ630 - Google Assistant. An ECO mode is only available for the AVENTAGE RX-A1080. Both AVENTAGE RX-A1080 and TX-RZ630 can be configured using the Setup assistant.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review.