An affordable AV receiver is always a good option to consider, so Onkyo TX-SR393 vs Pioneer VSX-S520 comparison definitely makes sense.
A significant difference between the receivers in the number of channels, Onkyo TX-SR393 has 5.2 versus 5.1 for Pioneer VSX-S520. Regarding power, then TX-SR393 has such a W/Ohm ratio - 80/8, 155/6 when VSX-S520 has a power of 50/4. The THD is 0.08% for the TX-SR393 but 0.09% for the VSX-S520.
Characteristics of digital to analog converter (DAC) are different, AKM 384 KHz/32-bit for TX-SR393 and 192 KHz/24-bit for the VSX-S520. None of the models support Bi-amping. The Pioneer VSX-S520 can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Rivals from our review have Bluetooth support. Only the VSX-S520 supports Spotify. 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.
Each receiver has 4/1 HDMI inputs/outputs. 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-S520 has a built-in phono stage for connecting a vinyl player. A voice control is not available. An ECO mode is not present in each of the AV receivers. The setup assistant will help you configure Pioneer VSX-S520.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review.