An affordable AV receiver is always a good option to consider, so Yamaha RX-V377 vs Onkyo TX-RZ730 comparison definitely makes sense.
A significant difference between the receivers in the number of channels, Yamaha RX-V377 has 5.1 versus 9.2 for Onkyo TX-RZ730. Regarding power, then RX-V377 has such a W/Ohm ratio - 100/8, 135/6 when TX-RZ730 has a power of 175/6. The THD is 0.09% for the RX-V377 but 0.08% for the TX-RZ730.
Characteristics of digital to analog converter (DAC) are different, Burr-Brown 192 KHz/24-bit for RX-V377 and AK4458 384 KHz/32-bit for the TX-RZ730. Only the TX-RZ730 supports Bi-amping feature. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Only the TX-RZ730 has Bluetooth support. Only the TX-RZ730 supports Spotify. 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 competitors are not able to scale the HDMI signal. Dolby Vision technology found support only on the TX-RZ730.
The Yamaha RX-V377 has 4/1 HDMI inputs/outputs versus 7/2 HDMI connectors of the Onkyo TX-RZ730. 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-RZ730 has a built-in phono stage for connecting a vinyl player. An ECO mode is only available for the RX-V377. Both RX-V377 and TX-RZ730 can be configured using the Setup assistant.
Only the TX-RZ730 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the TX-RZ730.