Having had an opportunity to test Onkyo TX-NR555 vs Pioneer SC-LX501, I’d like to share my impression here to facilitate your choice of a new AV receiver.
AV receivers under review have the same number of channels. In terms of power, there are differences, the TX-NR555 has such a ratio W/Ohm - 130/6, 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-NR555 received the model Hi-Grade 384 KHz/32-bit, but the SC-LX501 is equipped with AK4458 384 KHz/32-bit. Each of the compared opponents supports Bi-amping. Both Onkyo TX-NR555 and Pioneer SC-LX501 can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
These units have the same Wi-Fi modules. Each of the receivers has a Bluetooth connector. Both devices can work with such Apple Music services: AirPlay. Access to the Spotify service is on each of the competitors. The number of available streaming services varies for receivers, the Onkyo TX-NR555 works with Deezer, TIDAL, Pandora, but the Pioneer SC-LX501 works with Deezer, TIDAL, Pandora, TuneIn Radio.
Support for the HDR function can only boast of each of the AV receivers. The quality of 4K/60Hz signal remains unchanged when transmitting from a source to a TV or projector via HDMI for both receivers. Signaling over HDMI in standby mode can provide the TX-NR555 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-NR555 has 6/1, and the SC-LX501 has 7/2. HDMI Audio Return Channel is implemented in both devices. HDMI eARC is not supported by the TX-NR555 and the SC-LX501. When comparing receivers, it becomes clear that each of the rivals can work with HDMI CEC. TX-NR555 and SC-LX501 support the standard HDCP 2.2. Like most receivers, our models have a built-in phono stage for connecting a vinyl player.
Ability to create 2 Multi zones inherent in both AV receivers. Voice control of the basic functions of the receiver is not realized in both models. There is an ECO mode in TX-NR555. The Pioneer SC-LX501 can be properly configured using the setup assistant.
A Dolby Atmos multichannel audio format is available both models. A DTS:X surround technology is supported by devices from our comparison.