It makes sense comparing Onkyo TX-SR393 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, Onkyo TX-SR393 has 5.2 versus 2.0 for Onkyo TX-8020. Regarding power, then TX-SR393 has such a W/Ohm ratio - 80/8, 155/6 when TX-8020 has a power of 90/6. The THD is 0.08% for the TX-SR393 but 0.03% for the TX-8020.
Characteristics of digital to analog converter (DAC) are different, AKM 384 KHz/32-bit for TX-SR393 and 192 KHz/24-bit for the TX-8020. None of the models support Bi-amping. The Onkyo TX-8020 can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
Both models do not have WI-FI support. Only the TX-SR393 has Bluetooth support. Competitors do not have built-in Spotify service. Only the TX-SR393 provides HDMI signal transmission in standby mode. The TX-SR393 can scale the input HDMI signal, unlike the TX-8020. Dolby Vision technology found support only on the TX-SR393. Only the TX-SR393 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 TX-SR393. The TX-8020 has a built-in phono stage for connecting a vinyl player. A voice control is not available. An ECO mode is not present in each of the AV receivers. Unfortunately, the setup assistant is not available in each of the models.
Only the TX-SR393 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the TX-SR393.
The Onkyo TX-SR393 is better receiver in this comparison. Check Onkyo TX-SR393 price