An affordable AV receiver is always a good option to consider, so Denon AVR-S540BT vs Pioneer VSX-S520 comparison definitely makes sense.
A significant difference between the receivers in the number of channels, Denon AVR-S540BT has 5.2 versus 5.1 for Pioneer VSX-S520. Regarding power, then AVR-S540BT has such a W/Ohm ratio - 70/8, 90/6 when VSX-S520 has a power of 50/4. The THD is 0.08% for the AVR-S540BT but 0.09% for the VSX-S520.
Characteristics of digital to analog converter (DAC) are different, 192 KHz/32-bit for AVR-S540BT 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. Spotify can be used on each receiver. The AVR-S540BT can work with the audio stream from TIDAL, Pandora, and the VSX-S520 can receive a content from Deezer, TIDAL, TuneIn Radio.
These units support HDR technology. 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. The VSX-S520 can scale the input HDMI signal, unlike the AVR-S540BT. The HDR standard - Dolby Vision is supported by these receivers.
The Denon AVR-S540BT has 5/1 HDMI inputs/outputs versus 4/1 HDMI connectors of the Pioneer VSX-S520. 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 only available for the AVR-S540BT. Both AVR-S540BT and VSX-S520 can be configured using the Setup assistant.
Only the VSX-S520 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the VSX-S520.