An affordable AV receiver is always a good option to consider, so Sony STR-DH790 vs Onkyo TX-NR555 comparison definitely makes sense.
Considered AV receivers have the same number of channels 7.2. Regarding power, then STR-DH790 has such a W/Ohm ratio - 90/6 when TX-NR555 has a power of 130/6. The THD is 0.09% for the STR-DH790 but 0.08% for the TX-NR555.
Characteristics of digital to analog converter (DAC) are different, 192 KHz/24-bit for STR-DH790 and Hi-Grade 384 KHz/32-bit for the TX-NR555. Both the STR-DH790 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. 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-DH790.
The Sony STR-DH790 has 4/1 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-DH790. 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. 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-DH790.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review.