Having had an opportunity to test Onkyo TX-NR555 vs Pioneer VSX-933, 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 VSX-933 has a power of 80/8, 165/6. 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 VSX-933 is equipped with AK4458 384 KHz/32-bit. Each of the compared opponents supports Bi-amping. Both Onkyo TX-NR555 and Pioneer VSX-933 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 VSX-933 works with Deezer, TIDAL, Pandora, TuneIn Radio. 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 VSX-933. Video scaling is only possible with the VSX-933. Operation with the Dolby Vision is only possible with the VSX-933.
The number of HDMI inputs/outputs is the same - 6/1. HDMI Audio Return Channel is implemented in both devices. HDMI eARC is not supported by the TX-NR555 and the VSX-933. When comparing receivers, it becomes clear that each of the rivals can work with HDMI CEC. TX-NR555 and VSX-933 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. There is an ECO mode in TX-NR555. The Pioneer VSX-933 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.