Having had an opportunity to test Denon HEOS AVR vs Yamaha RX-A880, I’d like to share my impression here to facilitate your choice of a new AV receiver.
The number of channels for receivers is different - 5.1 versus 7.2, respectively, for devices. In terms of power, there are differences, the HEOS AVR has such a ratio W/Ohm - 50/8, 65/6, while the RX-A880 has a power of 100/8, 160/4. The value of total harmonic distortion is also different, and for the HEOS AVR it is 0.05%, but for the RX-A880 it is 0.06%. The Bi-amping function is implemented only in the Yamaha RX-A880. Both Denon HEOS AVR and Yamaha RX-A880 can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Each of the receivers has a Bluetooth connector. Access to the Spotify service is on each of the competitors. The number of available streaming services varies for receivers, the Denon HEOS AVR works with Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud, but the Yamaha RX-A880 works with Deezer, TIDAL, Pandora, Napster, SiriusXM, Qobuz. The quality of 4K/60Hz signal remains unchanged when transmitting from a source to a TV or projector via HDMI for both receivers. Signaling over HDMI in standby mode can provide the HEOS AVR and the RX-A880. Video scaling is only possible with the RX-A880. Operation with the Dolby Vision is only possible with the RX-A880.
The number of HDMI inputs/outputs varies depending on the receiver, the HEOS AVR has 4/1, and the RX-A880 has 7/2. HDMI Audio Return Channel is implemented in both devices. HDMI eARC is only supported by the RX-A880. When comparing receivers, it becomes clear that each of the rivals can work with HDMI CEC. HEOS AVR and RX-A880 support the standard HDCP 2.2. In the presence of a built-in phono stage for connecting a vinyl player only at Yamaha RX-A880. Voice control is performed using Amazon Alexa, Google Assistant in both models. There is an ECO mode in RX-A880. The Yamaha RX-A880 can be properly configured using the setup assistant.
A Dolby Atmos multichannel audio format is available only in the RX-A880. Only in the RX-A880 realized a DTS:X surround technology.