It makes sense comparing Yamaha RX-V385BL 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 RX-V385BL has 5.1 versus 9.2 for Onkyo TX-RZ630. Regarding power, then RX-V385BL has such a W/Ohm ratio - 70/8, 145/6 when TX-RZ630 has a power of 90/8, 215/6. The THD is 0.09% for the RX-V385BL but 0.08% for the TX-RZ630.
Characteristics of digital to analog converter (DAC) are different, Burr-Brown 384 KHz/32-bit for RX-V385BL and AK4458 384 KHz/32-bit for the TX-RZ630. Only the TX-RZ630 supports Bi-amping feature. The Onkyo TX-RZ630 can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Rivals from our review have Bluetooth support. Only the TX-RZ630 supports Spotify.
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 RX-V385BL can scale the input HDMI signal, unlike the TX-RZ630. The HDR standard - Dolby Vision is supported by these receivers.
The Yamaha RX-V385BL has 4/1 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 RX-V385BL. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. The RX-V385BL supports the protection of digital content of the standard HDCP 2.3, versus HDCP 2.2 in the TX-RZ630. The TX-RZ630 has a built-in phono stage for connecting a vinyl player. An ECO mode is only available for the RX-V385BL. The setup assistant will help you configure Onkyo TX-RZ630.
Only the TX-RZ630 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the TX-RZ630.