It makes sense comparing Marantz SR5012 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, Marantz SR5012 has 7.2 versus 7.1 for Yamaha RX-V671. Regarding power, then SR5012 has such a W/Ohm ratio - 100/8 when RX-V671 has a power of 90/8, 150/4. The THD is 0.08% for the SR5012 but 0.09% for the RX-V671.
Characteristics of digital to analog converter (DAC) are different, 192 KHz/24-bit for SR5012 and Burr-Brown 192 KHz/24-bit for the RX-V671. Both the SR5012 and the RX-V671 support Bi-amping. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Rivals from our review have Bluetooth support. Only the SR5012 supports Spotify. The SR5012 can work with the audio stream from Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud, and the RX-V671 can receive a content from Napster.
Only the Marantz SR5012 has support for High dynamic range (HDR). 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 SR5012.
The Marantz SR5012 has 8/2 HDMI inputs/outputs versus 6/1 HDMI connectors of the Yamaha RX-V671. 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 RX-V671 has a built-in phono stage for connecting a vinyl player.
Each of the AV receivers from our review supports 2 Multi-room zones. An ECO mode is only available for the SR5012. The setup assistant will help you configure Marantz SR5012.
Only the SR5012 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the SR5012.