The Onkyo TX-RZ730 vs Marantz AV7703 comparison proves that these receivers have many common features.
A significant difference between the receivers in the number of channels, Onkyo TX-RZ730 has 9.2 versus 11.2 for Marantz AV7703. The THD is the same and is 0.08%.
Characteristics of digital to analog converter (DAC) are different, AK4458 384 KHz/32-bit for TX-RZ730 and 192 KHz/32-bit for the AV7703. Both the TX-RZ730 and the AV7703 support Bi-amping. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
WI-FI modules have the same characteristics: 2.4/5GHz. Rivals from our review have Bluetooth support. The Onkyo TX-RZ730 has support for AirPlay, and its competitor in our comparison - AirPlay, AirPlay 2. Spotify can be used on each receiver. The TX-RZ730 can work with the audio stream from Deezer, TIDAL, TuneIn Radio, and the AV7703 can receive a content from Deezer, TIDAL, Pandora, Napster, iHeart Radio, SiriusXM, 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 AV7703 can scale the input HDMI signal, unlike the TX-RZ730. The HDR standard - Dolby Vision is supported by these receivers.
The Onkyo TX-RZ730 has 7/2 HDMI inputs/outputs versus 8/3 HDMI connectors of the Marantz AV7703. The HDMI Audio Return Channel (ARC) feature supports both devices. Unfortunately, HDMI eARC is not available on monitored devices. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. Both models support the standard HDCP 2.2. These compared receivers have a built-in phono stage for connecting a vinyl player.
Each of the AV receivers from our review supports 3 Multi-room zones. The TX-RZ730 supports voice control via Google Assistant, and the AV7703 - Amazon Alexa, Google Assistant, Siri, Josh.AI. An ECO mode is only available for the AV7703. Both TX-RZ730 and AV7703 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.