What is better - Denon AVR-S640H vs Yamaha RX-V6A?
The number of channels for receivers is different - 5.2 versus 7.2, respectively, for devices. In terms of power, there are differences, the AVR-S640H has such a ratio W/Ohm - 75/8, 100/6, while the RX-V6A has a power of 100/8. The value of total harmonic distortion is also different, and for the AVR-S640H it is 0.08%, but for the RX-V6A it is 0.06%. The Bi-amping function is implemented only in the Yamaha RX-V6A. Both Denon AVR-S640H and Yamaha RX-V6A can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Each of the receivers has a Bluetooth connector. Both devices can work with such Apple Music services: AirPlay, AirPlay 2. Access to the Spotify service is on each of the competitors. The number of available streaming services varies for receivers, the Denon AVR-S640H works with Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud, but the Yamaha RX-V6A works with Deezer, TIDAL, Pandora, SiriusXM, Qobuz. Signaling over HDMI in standby mode can provide the AVR-S640H and the RX-V6A. Video scaling is only possible with the RX-V6A. Each of the participants of the comparison has a Dolby Vision.
The number of HDMI inputs/outputs varies depending on the receiver, the AVR-S640H has 5/1, and the RX-V6A has 7/1. HDMI Audio Return Channel is implemented in both devices. HDMI eARC is only supported by the RX-V6A. When comparing receivers, it becomes clear that each of the rivals can work with HDMI CEC. The AVR-S640H has support for the standard HDCP 2.2, compared to the RX-V6A, which supports the standard HDCP 2.3. Like most receivers, our models have a built-in phono stage for connecting a vinyl player. For voice control in the AVR-S640H is used Amazon Alexa, Google Assistant, Siri, Josh.AI, but in the RX-V6A is used Amazon Alexa, Google Assistant, Siri. There is an ECO mode in either AV receiver. The Denon AVR-S640H and the Yamaha RX-V6A can be properly configured using the setup assistant.
A Dolby Atmos multichannel audio format is available only in the RX-V6A. Only in the RX-V6A realized a DTS:X surround technology.