It makes sense comparing Marantz NR1509 vs Yamaha RX-V671 because they both are able to give some premium features.
A significant difference between the receivers in the number of channels, Marantz NR1509 has 5.2 versus 7.1 for Yamaha RX-V671. Regarding power, then NR1509 has such a W/Ohm ratio - 50/8, 60/6 when RX-V671 has a power of 90/8, 150/4. The THD is 0.08% for the NR1509 but 0.09% for the RX-V671.
Characteristics of digital to analog converter (DAC) are different, 192 KHz/24-bit for NR1509 and Burr-Brown 192 KHz/24-bit for the RX-V671. Only the RX-V671 supports Bi-amping feature. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Rivals from our review have Bluetooth support. Only the NR1509 supports Spotify. The NR1509 can work with the audio stream from Deezer, Pandora, TuneIn Radio, and the RX-V671 can receive a content from Napster.
Only the Marantz NR1509 has support for High dynamic range (HDR). 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 RX-V671 can scale the input HDMI signal, unlike the NR1509. Dolby Vision technology found support only on the NR1509.
The Marantz NR1509 has 7/1 HDMI inputs/outputs versus 6/1 HDMI connectors of the Yamaha RX-V671. 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. These compared receivers have a built-in phono stage for connecting a vinyl player. An ECO mode is only available for the NR1509. The setup assistant will help you configure Marantz NR1509.
None of the rivals equipped with Dolby Atmos multichannel audio decoder. The receivers do not support the surround sound technology DTS:X.