An affordable AV receiver is always a good option to consider, so Marantz NR1510 vs Onkyo TX-8140 comparison definitely makes sense.
A significant difference between the receivers in the number of channels, Marantz NR1510 has 5.2 versus 2.0 for Onkyo TX-8140. Regarding power, then NR1510 has such a W/Ohm ratio - 50/8, 60/6 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/32-bit for NR1510 and AK4458 384 KHz/32-bit for the TX-8140. None of the models support Bi-amping. 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 NR1510 can work with the audio stream from Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, and the TX-8140 can receive a content from SiriusXM. Only the NR1510 provides HDMI signal transmission in standby mode. Both competitors are not able to scale the HDMI signal. Dolby Vision technology found support only on the NR1510. Only the NR1510 supports HDMI Audio Return Channel (ARC). The HDMI eARC is available only on the NR1510. Of the two receivers in our comparison, HDMI CEC is present in only the NR1510. These compared receivers have a built-in phono stage for connecting a vinyl player. An ECO mode is only available for the NR1510. Both NR1510 and TX-8140 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.