Having had an opportunity to test Marantz AV7703 vs Onkyo TX-NR616, 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 - 11.2 versus 7.2, respectively, for devices. A common feature for devices is the same total harmonic distortion - 0.08%.
The manufacturer installed different DACs, the AV7703 received the model 192 KHz/32-bit, but the TX-NR616 is equipped with Burr-Brown 192 KHz/24-bit. Each of the compared opponents supports Bi-amping. Both Marantz AV7703 and Onkyo TX-NR616 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 Marantz AV7703 works with Deezer, TIDAL, Pandora, Napster, iHeart Radio, SiriusXM, Sound Cloud, but the Onkyo TX-NR616 works with Last.fm, AUPEO, Simfy, vTuner.
Support for the HDR function can only boast of the AV7703. 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 AV7703 and the TX-NR616. Each of the devices can increase the resolution of the incoming video signal. Operation with the Dolby Vision is only possible with the AV7703.
The number of HDMI inputs/outputs varies depending on the receiver, the AV7703 has 8/3, and the TX-NR616 has 8/2. HDMI Audio Return Channel is implemented in both devices. HDMI eARC is not supported by the AV7703 and the TX-NR616. When comparing receivers, it becomes clear that each of the rivals can work with HDMI CEC. AV7703 and TX-NR616 support the standard HDCP 2.2. In the presence of a built-in phono stage for connecting a vinyl player only at Marantz AV7703.
Unlike the AV7703 where 3 Multi zones is provided, the TX-NR616 works with 2 Multi zones. There is an ECO mode in AV7703. The Marantz AV7703 can be properly configured using the setup assistant.
A Dolby Atmos multichannel audio format is available only in the AV7703. Only in the AV7703 realized a DTS:X surround technology.