An affordable AV receiver is always a good option to consider, so Yamaha RX-A780 vs Pioneer VSX-S520 comparison definitely makes sense.
A significant difference between the receivers in the number of channels, Yamaha RX-A780 has 7.2 versus 5.1 for Pioneer VSX-S520. Regarding power, then RX-A780 has such a W/Ohm ratio - 95/8, 160/4 when VSX-S520 has a power of 50/4. The THD is 0.06% for the RX-A780 but 0.09% for the VSX-S520.
Characteristics of digital to analog converter (DAC) are different, Burr-Brown 384 KHz/32-bit for RX-A780 and 192 KHz/24-bit for the VSX-S520. Only the RX-A780 supports Bi-amping feature. Each of the AV receivers 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 Yamaha RX-A780 has support for AirPlay, AirPlay 2, and its competitor in our comparison - AirPlay. Spotify can be used on each receiver. The RX-A780 can work with the audio stream from Deezer, TIDAL, Pandora, Napster, SiriusXM, Qobuz, and the VSX-S520 can receive a content from Deezer, TIDAL, TuneIn Radio. 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. The HDR standard - Dolby Vision is supported by these receivers.
The Yamaha RX-A780 has 7/2 HDMI inputs/outputs versus 4/1 HDMI connectors of the Pioneer VSX-S520. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the RX-A780. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. The RX-A780 supports the protection of digital content of the standard HDCP 2.3, versus HDCP 2.2 in the VSX-S520. These compared receivers have a built-in phono stage for connecting a vinyl player. An ECO mode is only available for the RX-A780. Both RX-A780 and VSX-S520 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.