It makes sense comparing Denon AVR-S750H 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, Denon AVR-S750H has 7.2 versus 7.1 for Yamaha RX-V671. Regarding power, then AVR-S750H has such a W/Ohm ratio - 75/8, 110/6 when RX-V671 has a power of 90/8, 150/4. The THD is 0.08% for the AVR-S750H but 0.09% for the RX-V671.
Characteristics of digital to analog converter (DAC) are different, AKM 192 KHz/32-bit for AVR-S750H 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.
Only the Denon AVR-S750H can connect to the Internet via WI-FI. Rivals from our review have Bluetooth support. Only the AVR-S750H supports Spotify. The AVR-S750H can work with the audio stream from Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud, Mood Mix, and the RX-V671 can receive a content from Napster. 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-V671 can scale the input HDMI signal, unlike the AVR-S750H. Dolby Vision technology found support only on the AVR-S750H.
Each receiver has 6/1 HDMI inputs/outputs. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the AVR-S750H. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. The AVR-S750H supports the protection of digital content of the standard HDCP 2.3, versus HDCP 2.2 in the RX-V671. These compared receivers have 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 AVR-S750H. The setup assistant will help you configure Denon AVR-S750H.
Only the AVR-S750H has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the AVR-S750H.