Having had an opportunity to test Onkyo TX-SR353 vs Pioneer SC-LX501, 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 - 5.1 versus 7.2, respectively, for devices. In terms of power, there are differences, the TX-SR353 has such a ratio W/Ohm - 140/6, while the SC-LX501 has a power of 120/8, 180/6. A common feature for devices is the same total harmonic distortion - 0.08%.
The manufacturer installed different DACs, the TX-SR353 received the model 192 KHz/24-bit, but the SC-LX501 is equipped with AK4458 384 KHz/32-bit. The Bi-amping function is implemented only in the Pioneer SC-LX501. The model SC-LX501 can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Each of the receivers has a Bluetooth connector. The SC-LX501 has access to the Spotify service.
Support for the HDR function can only boast of the SC-LX501. Signaling over HDMI in standby mode can provide the TX-SR353 and the SC-LX501. Video scaling is only possible with the SC-LX501. Operation with the Dolby Vision is only possible with the SC-LX501.
The number of HDMI inputs/outputs varies depending on the receiver, the TX-SR353 has 4/1, and the SC-LX501 has 7/2. HDMI Audio Return Channel is implemented in both devices. HDMI eARC is not supported by the TX-SR353 and the SC-LX501. When comparing receivers, it becomes clear that each of the rivals can work with HDMI CEC. TX-SR353 and SC-LX501 support the standard HDCP 2.2. In the presence of a built-in phono stage for connecting a vinyl player only at Pioneer SC-LX501. Voice control of the basic functions of the receiver is not realized in both models. There is an ECO mode in neither AV receiver. The Pioneer SC-LX501 can be properly configured using the setup assistant.
A Dolby Atmos multichannel audio format is available only in the SC-LX501. Only in the SC-LX501 realized a DTS:X surround technology.