It makes sense comparing Pioneer VSX-LX303 vs Yamaha RX-V671 because they both are able to give some premium features.
A significant difference between the receivers in the number of channels, Pioneer VSX-LX303 has 9.2 versus 7.1 for Yamaha RX-V671. Regarding power, then VSX-LX303 has such a W/Ohm ratio - 100/8, 200/6 when RX-V671 has a power of 90/8, 150/4. The THD is 0.08% for the VSX-LX303 but 0.09% for the RX-V671.
Characteristics of digital to analog converter (DAC) are different, AK4458 384 KHz/32-bit for VSX-LX303 and Burr-Brown 192 KHz/24-bit for the RX-V671. Both the VSX-LX303 and the RX-V671 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 VSX-LX303 supports Spotify. The VSX-LX303 can work with the audio stream from Deezer, TIDAL, Pandora, TuneIn Radio, and the RX-V671 can receive a content from Napster. 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 rivals can scale the resolution of the incoming HDMI signal. Dolby Vision technology found support only on the VSX-LX303.
The Pioneer VSX-LX303 has 7/2 HDMI inputs/outputs versus 6/1 HDMI connectors of the Yamaha RX-V671. 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. These compared receivers have a built-in phono stage for connecting a vinyl player.
The VSX-LX303 supports 3 Multi-room zones, versus 2 for the RX-V671. 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.