An affordable AV receiver is always a good option to consider, so Pioneer VSX-LX303 vs Sony STR DH550 comparison definitely makes sense.
A significant difference between the receivers in the number of channels, Pioneer VSX-LX303 has 9.2 versus 5.2 for Sony STR DH550. Regarding power, then VSX-LX303 has such a W/Ohm ratio - 100/8, 200/6 when STR DH550 has a power of 90/6. The THD is 0.08% for the VSX-LX303 but 0.09% for the STR DH550.
Characteristics of digital to analog converter (DAC) are different, AK4458 384 KHz/32-bit for VSX-LX303 and 192 KHz/24-bit for the STR DH550. Only the VSX-LX303 supports Bi-amping feature. The Pioneer VSX-LX303 can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Only the VSX-LX303 has Bluetooth support. Only the VSX-LX303 supports Spotify. Only the VSX-LX303 provides HDMI signal transmission in standby mode. The VSX-LX303 can scale the input HDMI signal, unlike the STR DH550. Dolby Vision technology found support only on the VSX-LX303.
The Pioneer VSX-LX303 has 7/2 HDMI inputs/outputs versus 4/1 HDMI connectors of the Sony STR DH550. 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. The VSX-LX303 has a built-in phono stage for connecting a vinyl player. An ECO mode is not present in each of the AV receivers. The setup assistant will help you configure Pioneer VSX-LX303.
Only the VSX-LX303 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the VSX-LX303.