It makes sense comparing Yamaha RX-V385 vs Yamaha RX-V671 because they both are able to give some premium features.
A significant difference between the receivers in the number of channels, Yamaha RX-V385 has 5.1 versus 7.1 for Yamaha RX-V671. Regarding power, then RX-V385 has such a W/Ohm ratio - 70/6 when RX-V671 has a power of 90/8, 150/4. The THD is the same and is 0.09%.
Characteristics of digital to analog converter (DAC) are different, Burr-Brown 384 KHz/32-bit for RX-V385 and Burr-Brown 192 KHz/24-bit for the RX-V671. Only the RX-V671 supports Bi-amping feature. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
Both models do not have WI-FI support. Rivals from our review have Bluetooth support. Competitors do not have built-in Spotify service. 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. Dolby Vision technology found support only on the RX-V385.
The Yamaha RX-V385 has 4/1 HDMI inputs/outputs versus 6/1 HDMI connectors of the Yamaha RX-V671. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the RX-V385. 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 RX-V671 has a built-in phono stage for connecting a vinyl player. A voice control is not available. An ECO mode is only available for the RX-V385. Unfortunately, the setup assistant is not available in each of the models.
None of the rivals equipped with Dolby Atmos multichannel audio decoder. The receivers do not support the surround sound technology DTS:X.