It makes sense comparing Sony STR DH550 vs Yamaha RX-V485 because they both are able to give some premium features.
A significant difference between the receivers in the number of channels, Sony STR DH550 has 5.2 versus 5.1 for Yamaha RX-V485. Regarding power, then STR DH550 has such a W/Ohm ratio - 90/6 when RX-V485 has a power of 80/8, 145/6. The THD is the same and is 0.09%.
Characteristics of digital to analog converter (DAC) are different, 192 KHz/24-bit for STR DH550 and Burr-Brown 384 KHz/32-bit for the RX-V485. Only the RX-V485 supports Bi-amping feature. The Yamaha RX-V485 can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
Only the Yamaha RX-V485 can connect to the Internet via WI-FI. Only the RX-V485 has Bluetooth support. Only the RX-V485 supports Spotify. Only the RX-V485 provides HDMI signal transmission in standby mode. The RX-V485 can scale the input HDMI signal, unlike the STR DH550. Dolby Vision technology found support only on the RX-V485.
Each receiver has 4/1 HDMI inputs/outputs. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the RX-V485. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. The STR DH550 supports the protection of digital content of the standard HDCP 2.2, versus HDCP 2.3 in the RX-V485. Receivers do not have a built-in phono stage for connecting a vinyl player. An ECO mode is only available for the RX-V485. The setup assistant will help you configure Yamaha RX-V485.
None of the rivals equipped with Dolby Atmos multichannel audio decoder. The receivers do not support the surround sound technology DTS:X.