It’s strongly recommended to compare different receivers if you want to choose the best one: Onkyo TX-NR555 vs Marantz NR1508.
The number of channels for receivers is different - 7.2 versus 5.2, respectively, for devices. In terms of power, there are differences, the TX-NR555 has such a ratio W/Ohm - 130/6, while the NR1508 has a power of 50/8. A common feature for devices is the same total harmonic distortion - 0.08%.
The manufacturer installed different DACs, the TX-NR555 received the model Hi-Grade 384 KHz/32-bit, but the NR1508 is equipped with 192 KHz/24-bit. The Bi-amping function is implemented only in the Onkyo TX-NR555. Both Onkyo TX-NR555 and Marantz NR1508 can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
These units have the same Wi-Fi modules. 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. Most popular streaming services are available for our models under consideration - Deezer, TIDAL, Pandora.
Support for the HDR function can only boast of each of the AV receivers. 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 TX-NR555 and the NR1508. None of the devices can increase the resolution of the incoming video signal. Operation with the Dolby Vision is only possible with the NR1508.
The number of HDMI inputs/outputs is the same - 6/1. HDMI Audio Return Channel is only available on Onkyo TX-NR555. HDMI eARC is not supported by the TX-NR555 and the NR1508. When comparing receivers, it becomes clear that each of the rivals can work with HDMI CEC. TX-NR555 and NR1508 support the standard HDCP 2.2. In the presence of a built-in phono stage for connecting a vinyl player only at Onkyo TX-NR555. There is an ECO mode in either AV receiver. The Marantz NR1508 can be properly configured using the setup assistant.
A Dolby Atmos multichannel audio format is available only in the TX-NR555. Only in the TX-NR555 realized a DTS:X surround technology.