Onkyo TX-NR555 vs Denon AVR-S510BT comparison definitely makes sense.
A significant difference between the receivers in the number of channels, Onkyo TX-NR555 has 7.2 versus 5.2 for Denon AVR-S510BT. Regarding power, then TX-NR555 has such a W/Ohm ratio - 130/6 when AVR-S510BT has a power of 75/8, 110/6. The THD is the same and is 0.08%.
Characteristics of digital to analog converter (DAC) are different, Hi-Grade 384 KHz/32-bit for TX-NR555 and 192 KHz/32-bit for the AVR-S510BT. Only the TX-NR555 supports Bi-amping feature. The Onkyo TX-NR555 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.
Only the Onkyo TX-NR555 has support for High dynamic range (HDR). 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. The HDR standard - Dolby Vision is not supported by these receivers.
The Onkyo TX-NR555 has 6/1 HDMI inputs/outputs versus 5/1 HDMI connectors of the Denon AVR-S510BT. Only the TX-NR555 supports HDMI Audio Return Channel (ARC). Unfortunately, HDMI eARC is not available on monitored devices. Of the two receivers in our comparison, HDMI CEC is present in only the TX-NR555. 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 Denon AVR-S510BT.
Only the TX-NR555 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the TX-NR555.