Yamaha RX-V4A vs Denon AVR-S670H comparison definitely makes sense.
Considered AV receivers have the same number of channels 5.2. Regarding power, then RX-V4A has such a W/Ohm ratio - 80/6 when AVR-S670H has a power of 75/8, 100/6. The THD is 0.06% for the RX-V4A but 0.08% for the AVR-S670H. Only the RX-V4A supports Bi-amping feature. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
WI-FI modules have the same characteristics: 2.4/5GHz. Rivals from our review have Bluetooth support. The Apple Music service is implemented on considered devices: AirPlay, AirPlay 2. Spotify can be used on each receiver. The RX-V4A can work with the audio stream from Deezer, TIDAL, Pandora, SiriusXM, Qobuz, and the AVR-S670H can receive a content from Deezer, TIDAL, Pandora, SiriusXM, Napster, SoundCloud, Amazon Music, Amazon Music HD, MOOD:Mix.
Compared AV receivers retain the quality of 4K/120Hz 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. The HDR standard - Dolby Vision is supported by these receivers.
The Yamaha RX-V4A has 4/1 HDMI inputs/outputs versus 6/1 HDMI connectors of the Denon AVR-S670H. The HDMI Audio Return Channel (ARC) feature supports both devices. HDMI eARC is available in each model. 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 2.3. The AVR-S670H has a built-in phono stage for connecting a vinyl player. The RX-V4A supports voice control via Amazon Alexa, Google Assistant, Siri, and the AVR-S670H - Amazon Alexa, Google Assistant, Siri, Josh.AI. It is also worth noting that the ECO mode is presented in each of the receivers. Both RX-V4A and AVR-S670H 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.