It’s strongly recommended to compare different receivers if you want to choose the best one: Pioneer VSX-S520 vs Pioneer VSX-531.
AV receivers under review have the same number of channels. In terms of power, there are differences, the VSX-S520 has such a ratio W/Ohm - 50/4, while the VSX-531 has a power of 80/8, 140/6. The value of total harmonic distortion is also different, and for the VSX-S520 it is 0.09%, but for the VSX-531 it is 0.08%.
Competitive models use the same DAC. None of the compared opponents supports Bi-amping. Both Pioneer VSX-S520 and Pioneer VSX-531 can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Each of the receivers has a Bluetooth connector. The VSX-S520 has access to the Spotify service.
Support for the HDR function can only boast of each of the AV receivers. The quality of 4K/60Hz signal remains unchanged when transmitting from a source to a TV or projector via HDMI for both receivers. Signaling over HDMI in standby mode can provide the VSX-S520 and the VSX-531. Video scaling is only possible with the VSX-S520. Operation with the Dolby Vision is only possible with the VSX-S520.
The number of HDMI inputs/outputs is the same - 4/1. HDMI Audio Return Channel is implemented in both devices. HDMI eARC is not supported by the VSX-S520 and the VSX-531. When comparing receivers, it becomes clear that each of the rivals can work with HDMI CEC. VSX-S520 and VSX-531 support the standard HDCP 2.2. In the presence of a built-in phono stage for connecting a vinyl player only at Pioneer VSX-S520. Voice control of the basic functions of the receiver is not realized in both models. There is an ECO mode in VSX-531. The Pioneer VSX-S520 can be properly configured using the setup assistant.
A Dolby Atmos multichannel audio format is available only in the VSX-S520. Only in the VSX-S520 realized a DTS:X surround technology.