An affordable AV receiver is always a good option to consider, so Marantz NR1609 vs Onkyo TX-8140 comparison definitely makes sense.
A significant difference between the receivers in the number of channels, Marantz NR1609 has 7.2 versus 2.0 for Onkyo TX-8140. Regarding power, then NR1609 has such a W/Ohm ratio - 50/8, 70/6 when TX-8140 has a power of 80/8, 110/6. The THD is the same and is 0.08%.
Characteristics of digital to analog converter (DAC) are different, 192 KHz/24-bit for NR1609 and AK4458 384 KHz/32-bit for the TX-8140. Only the NR1609 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. Spotify can be used on each receiver. The NR1609 can work with the audio stream from Deezer, Pandora, TuneIn Radio, and the TX-8140 can receive a content from SiriusXM.
Only the Marantz NR1609 has support for High dynamic range (HDR). Only the NR1609 provides HDMI signal transmission in standby mode. The NR1609 can scale the input HDMI signal, unlike the TX-8140. Dolby Vision technology found support only on the NR1609. Only the NR1609 supports HDMI Audio Return Channel (ARC). Unfortunately, HDMI eARC is not available on monitored devices. Of the two receivers in our comparison, HDMI CEC is present in only the NR1609. These compared receivers have a built-in phono stage for connecting a vinyl player. An ECO mode is only available for the NR1609. Both NR1609 and TX-8140 can be configured using the Setup assistant.
Only the NR1609 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the NR1609.