It makes sense comparing Yamaha AVENTAGE RX-A680 vs Onkyo TX-8020 because they both are able to give some premium features.
A significant difference between the receivers in the number of channels, Yamaha AVENTAGE RX-A680 has 7.2 versus 2.0 for Onkyo TX-8020. Regarding power, then AVENTAGE RX-A680 has such a W/Ohm ratio - 115/8, 145/6 when TX-8020 has a power of 90/6. The THD is 0.08% for the AVENTAGE RX-A680 but 0.03% for the TX-8020.
Characteristics of digital to analog converter (DAC) are different, Burr-Brown 384 KHz/32-bit for AVENTAGE RX-A680 and 192 KHz/24-bit for the TX-8020. Only the AVENTAGE RX-A680 supports Bi-amping feature. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Only the AVENTAGE RX-A680 has Bluetooth support. The Yamaha AVENTAGE RX-A680 has support for AirPlay, AirPlay 2, and its competitor in our comparison - AirPlay. Only the AVENTAGE RX-A680 supports Spotify. Only the AVENTAGE RX-A680 provides HDMI signal transmission in standby mode. The AVENTAGE RX-A680 can scale the input HDMI signal, unlike the TX-8020. Dolby Vision technology found support only on the AVENTAGE RX-A680. Only the AVENTAGE RX-A680 supports HDMI Audio Return Channel (ARC). The HDMI eARC is available only on the AVENTAGE RX-A680. Of the two receivers in our comparison, HDMI CEC is present in only the AVENTAGE RX-A680. The TX-8020 has a built-in phono stage for connecting a vinyl player. An ECO mode is only available for the AVENTAGE RX-A680. The setup assistant will help you configure Yamaha AVENTAGE RX-A680.
Only the AVENTAGE RX-A680 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the AVENTAGE RX-A680.
The Yamaha AVENTAGE RX-A680 is better receiver in this comparison. Check Yamaha AVENTAGE RX-A680 price