An affordable AV receiver is always a good option to consider, so Yamaha AVENTAGE RX-A680 vs Denon AVR-S740H comparison definitely makes sense.
Considered AV receivers have the same number of channels 7.2. Regarding power, then AVENTAGE RX-A680 has such a W/Ohm ratio - 115/8, 145/6 when AVR-S740H has a power of 75/8, 110/6. The THD is the same and is 0.08%.
Characteristics of digital to analog converter (DAC) are different, Burr-Brown 384 KHz/32-bit for AVENTAGE RX-A680 and 192 KHz/32-bit for the AVR-S740H. Only the AVENTAGE RX-A680 supports Bi-amping feature. 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. The Apple Music service is implemented on considered devices: AirPlay, AirPlay 2. Spotify can be used on each receiver. The AVENTAGE RX-A680 can work with the audio stream from Deezer, TIDAL, Pandora, Napster, SiriusXM, Qobuz, and the AVR-S740H can receive a content from Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud. 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 AVENTAGE RX-A680 can scale the input HDMI signal, unlike the AVR-S740H. The HDR standard - Dolby Vision is supported by these receivers.
The Yamaha AVENTAGE RX-A680 has 4/1 HDMI inputs/outputs versus 6/1 HDMI connectors of the Denon AVR-S740H. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the AVENTAGE RX-A680. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. The AVENTAGE RX-A680 supports the protection of digital content of the standard HDCP 2.3, versus HDCP 2.2 in the AVR-S740H. The AVR-S740H has a built-in phono stage for connecting a vinyl player.
Each of the AV receivers from our review supports 2 Multi-room zones. The AVENTAGE RX-A680 supports voice control via Amazon Alexa, Google Assistant, and the AVR-S740H - Amazon Alexa, Google Assistant, Siri, Josh.AI. It is also worth noting that the ECO mode is presented in each of the receivers. Both AVENTAGE RX-A680 and AVR-S740H can be configured using the Setup assistant.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review.