Having had an opportunity to test Onkyo TX-SR383 vs Pioneer Elite VSX-LX505, I’d like to share my impression here to facilitate your choice of a new AV receiver.
The number of channels for receivers is different - 7.2 versus 9.2, respectively, for devices. In terms of power, there are differences, the TX-SR383 has such a ratio W/Ohm - 100/8, 135/6, while the Elite VSX-LX505 has a power of 120/8, 230/6. The value of total harmonic distortion is also different, and for the TX-SR383 it is 0.09%, but for the Elite VSX-LX505 it is 0.08%.
Competitive models use the same DAC. The Bi-amping function is implemented only in the Pioneer Elite VSX-LX505. In the considered devices there is no function transmitting an audio signal directly to the amplifier and bypasses any DSP processing. Each of the receivers has a Bluetooth connector. The Elite VSX-LX505 has access to the Spotify service. Signaling over HDMI in standby mode can provide the TX-SR383 and the Elite VSX-LX505. Video scaling is only possible with the Elite VSX-LX505. Operation with the Dolby Vision is only possible with the Elite VSX-LX505.
The number of HDMI inputs/outputs varies depending on the receiver, the TX-SR383 has 4/1, and the Elite VSX-LX505 has 7/2. HDMI Audio Return Channel is implemented in both devices. HDMI eARC is only supported by the Elite VSX-LX505. When comparing receivers, it becomes clear that only the Onkyo TX-SR383 has HDMI CEC. The TX-SR383 has support for the standard HDCP 2.2, compared to the Elite VSX-LX505, which supports the standard HDCP 2.3. In the presence of a built-in phono stage for connecting a vinyl player only at Pioneer Elite VSX-LX505.
Ability to create 2 Multi zones inherent in both AV receivers. There is an ECO mode in neither AV receiver. The Pioneer Elite VSX-LX505 can be properly configured using the setup assistant.
A Dolby Atmos multichannel audio format is available only in the Elite VSX-LX505. Only in the Elite VSX-LX505 realized a DTS:X surround technology.