The Pioneer VSX-LX303 vs Denon AVR-S660H comparison proves that these receivers have many common features.
A significant difference between the receivers in the number of channels, Pioneer VSX-LX303 has 9.2 versus 5.2 for Denon AVR-S660H. Regarding power, then VSX-LX303 has such a W/Ohm ratio - 100/8, 200/6 when AVR-S660H has a power of 75/8, 100/6. The THD is the same and is 0.08%.
Characteristics of digital to analog converter (DAC) are different, AK4458 384 KHz/32-bit for VSX-LX303 and 192 KHz/32-bit for the AVR-S660H. 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.
WI-FI modules have the same characteristics: 2.4/5GHz. Rivals from our review have Bluetooth support. The Pioneer VSX-LX303 has support for AirPlay, and its competitor in our comparison - AirPlay, AirPlay 2. Spotify can be used on each receiver. The VSX-LX303 can work with the audio stream from Deezer, TIDAL, Pandora, TuneIn Radio, and the AVR-S660H can receive a content from Deezer, TIDAL, Pandora, SiriusXM, Napster, SoundCloud.
HDMI signal transmission in standby mode is implemented in each of the devices. Both rivals can scale the resolution of the incoming HDMI signal. The HDR standard - Dolby Vision is supported by these receivers.
The Pioneer VSX-LX303 has 7/2 HDMI inputs/outputs versus 6/1 HDMI connectors of the Denon AVR-S660H. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the AVR-S660H. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. The VSX-LX303 supports the protection of digital content of the standard HDCP 2.2, versus HDCP 2.3 in the AVR-S660H. These compared receivers have a built-in phono stage for connecting a vinyl player. The VSX-LX303 supports voice control via Google Assistant, and the AVR-S660H - Amazon Alexa, Google Assistant, Siri, Josh.AI. An ECO mode is only available for the AVR-S660H. Both VSX-LX303 and AVR-S660H can be configured using the Setup assistant.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review.