It makes sense comparing Yamaha RX-V377 vs Yamaha RX-V485 because they both are able to give some premium features.
Considered AV receivers have the same number of channels 5.1. Regarding power, then RX-V377 has such a W/Ohm ratio - 100/8, 135/6 when RX-V485 has a power of 80/8, 145/6. The THD is the same and is 0.09%.
Characteristics of digital to analog converter (DAC) are different, Burr-Brown 192 KHz/24-bit for RX-V377 and Burr-Brown 384 KHz/32-bit for the RX-V485. Only the RX-V485 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 Yamaha RX-V485 can connect to the Internet via WI-FI. Only the RX-V485 has Bluetooth support. Only the RX-V485 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. The RX-V485 can scale the input HDMI signal, unlike the RX-V377. Dolby Vision technology found support only on the RX-V485.
Each receiver has 4/1 HDMI inputs/outputs. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the RX-V485. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. The RX-V377 supports the protection of digital content of the standard HDCP 2.2, versus HDCP 2.3 in the RX-V485. Receivers do not have a built-in phono stage for connecting a vinyl player. It is also worth noting that the ECO mode is presented in each of the receivers. Both RX-V377 and RX-V485 can be configured using the Setup assistant.
None of the rivals equipped with Dolby Atmos multichannel audio decoder. The receivers do not support the surround sound technology DTS:X.