It makes sense comparing Onkyo TX-SR494 vs Onkyo TX-RZ710 because they both are able to give some premium features.
Considered AV receivers have the same number of channels 7.2. Regarding power, then TX-SR494 has such a W/Ohm ratio - 135/6 when TX-RZ710 has a power of 175/6. The THD is the same and is 0.08%.
Characteristics of digital to analog converter (DAC) are different, AKM 384 KHz/32-bit for TX-SR494 and AK4458 384 KHz/32-bit for the TX-RZ710. Both the TX-SR494 and the TX-RZ710 support Bi-amping. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Rivals from our review have Bluetooth support. Only the TX-RZ710 supports Spotify. 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 TX-RZ710 can scale the input HDMI signal, unlike the TX-SR494. The HDR standard - Dolby Vision is not supported by these receivers.
The Onkyo TX-SR494 has 4/1 HDMI inputs/outputs versus 8/2 HDMI connectors of the Onkyo TX-RZ710. 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. The TX-RZ710 has a built-in phono stage for connecting a vinyl player.
Each of the AV receivers from our review supports 2 Multi-room zones. A voice control is not available. An ECO mode is only available for the TX-RZ710. The setup assistant will help you configure Onkyo TX-SR494.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review.