Having had an opportunity to test Marantz NR1504 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 NR1504 has such a ratio W/Ohm - 50/8, 60/6, while the RX-A880 has a power of 100/8, 160/4. The value of total harmonic distortion is also different, and for the NR1504 it is 0.08%, but for the RX-A880 it is 0.06%.
The manufacturer installed different DACs, the NR1504 received the model 192 KHz/24-bit, but the RX-A880 is equipped with Burr-Brown 384 KHz/32-bit. The Bi-amping function is implemented only in the Yamaha RX-A880. Both Marantz NR1504 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. The contenders have differences in the supported services from Apple - AirPlay versus AirPlay, AirPlay 2 respectively. Access to the Spotify service is on each of the competitors. The number of available streaming services varies for receivers, the Marantz NR1504 works with Pandora, SiriusXM, but the Yamaha RX-A880 works with Deezer, TIDAL, Pandora, Napster, SiriusXM, Qobuz. Signaling over HDMI in standby mode can provide the NR1504 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 NR1504 has 6/1, 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. NR1504 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. There is an ECO mode in RX-A880. The Marantz NR1504 and 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.