Yamaha RX-S602 vs Yamaha RX-V4A comparison definitely makes sense.
A significant difference between the receivers in the number of channels, Yamaha RX-S602 has 5.1 versus 5.2 for Yamaha RX-V4A. Regarding power, then RX-S602 has such a W/Ohm ratio - 80/8, 125/6 when RX-V4A has a power of 80/6. The THD is 0.08% for the RX-S602 but 0.06% for the RX-V4A. Both the RX-S602 and the RX-V4A support Bi-amping. 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 Apple Music service is implemented on considered devices: AirPlay, AirPlay 2. Spotify can be used on each receiver. The RX-S602 can work with the audio stream from Deezer, TIDAL, Pandora, Napster, SiriusXM, Qobuz, and the RX-V4A can receive a content from Deezer, TIDAL, Pandora, SiriusXM, Qobuz.
Both AV receivers support HDR10 technology (High dynamic range). HDMI signal transmission in standby mode is implemented in each of the devices. The RX-V4A can scale the input HDMI signal, unlike the RX-S602. Dolby Vision technology found support only on the RX-V4A.
Each receiver has 4/1 HDMI inputs/outputs. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the RX-V4A. 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 2.3. Receivers do not have a built-in phono stage for connecting a vinyl player. The RX-S602 supports voice control via Amazon Alexa, Google Assistant, and the RX-V4A - Amazon Alexa, Google Assistant, Siri. It is also worth noting that the ECO mode is presented in each of the receivers. Both RX-S602 and RX-V4A can be configured using the Setup assistant.
None of the rivals equipped with Dolby Atmos multichannel audio decoder. The receivers do not support the surround sound technology DTS:X.