The Yamaha RX-V685BL vs Denon AVR-S660H comparison proves that these receivers have many common features.
A significant difference between the receivers in the number of channels, Yamaha RX-V685BL has 7.2 versus 5.2 for Denon AVR-S660H. Regarding power, then RX-V685BL has such a W/Ohm ratio - 90/8, 150/4 when AVR-S660H has a power of 75/8, 100/6. The THD is 0.06% for the RX-V685BL but 0.08% for the AVR-S660H.
Characteristics of digital to analog converter (DAC) are different, Burr-Brown 384 KHz/32-bit for RX-V685BL and 192 KHz/32-bit for the AVR-S660H. Only the RX-V685BL supports Bi-amping feature. The Yamaha RX-V685BL 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 Yamaha RX-V685BL has support for AirPlay, and its competitor in our comparison - AirPlay, AirPlay 2. Only the AVR-S660H supports Spotify.
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.
The Yamaha RX-V685BL has 5/2 HDMI inputs/outputs versus 6/1 HDMI connectors of the Denon AVR-S660H. The HDMI Audio Return Channel (ARC) feature supports both devices. HDMI eARC is available in each model. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. The RX-V685BL supports the protection of digital content of the standard HDCP 2.2, versus HDCP 2.3 in the AVR-S660H. These compared receivers have a built-in phono stage for connecting a vinyl player. It is also worth noting that the ECO mode is presented in each of the receivers. Both RX-V685BL and AVR-S660H can be configured using the Setup assistant.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review.