An affordable AV receiver is always a good option to consider, so Sony STR-ZA3100ES vs Onkyo TX-NR555 comparison definitely makes sense.
Considered AV receivers have the same number of channels 7.2. Regarding power, then STR-ZA3100ES has such a W/Ohm ratio - 70/8, 90/6 when TX-NR555 has a power of 130/6. The THD is 0.09% for the STR-ZA3100ES but 0.08% for the TX-NR555. Both the STR-ZA3100ES and the TX-NR555 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-NR555 supports Spotify.
These units support HDR technology. 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. Both competitors are not able to scale the HDMI signal. Dolby Vision technology found support only on the STR-ZA3100ES.
The Sony STR-ZA3100ES has 6/2 HDMI inputs/outputs versus 6/1 HDMI connectors of the Onkyo TX-NR555. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the STR-ZA3100ES. 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-NR555 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-NR555. The setup assistant will help you configure Sony STR-ZA3100ES.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review.