It makes sense comparing Onkyo TX-NR545 vs Yamaha RX-A750 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-NR545 has such a W/Ohm ratio - 100/6 when RX-A750 has a power of 90/6, 150/8, 150/4. The THD is 0.08% for the TX-NR545 but 0.06% for the RX-A750.
Characteristics of digital to analog converter (DAC) are different, Hi-Grade 384 KHz/32-bit for TX-NR545 and Burr-Brown 192 KHz/24-bit for the RX-A750. Both the TX-NR545 and the RX-A750 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. The Apple Music service is implemented on considered devices: AirPlay. Spotify can be used on each receiver. The TX-NR545 can work with the audio stream from Tunein Radio, and the RX-A750 can receive a content from Pandora, Napster, JUKE, Rhapsody.
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. The RX-A750 can scale the input HDMI signal, unlike the TX-NR545. The HDR standard - Dolby Vision is not supported by these receivers.
Each receiver has 6/1 HDMI inputs/outputs. 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. Receivers do not have 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 RX-A750. Both TX-NR545 and RX-A750 can be configured using the Setup assistant.
Both devices have support for Dolby Atmos multichannel audio format. The receivers do not support the surround sound technology DTS:X.