Having had an opportunity to test Pioneer Elite SC-LX704 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 - 9.2 versus 7.2, respectively, for devices. In terms of power, there are differences, the Elite SC-LX704 has such a ratio W/Ohm - 135/8, 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 Elite SC-LX704 received the model ES9026PRO 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 Pioneer Elite SC-LX704 and Pioneer 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 contenders have differences in the supported services from Apple - AirPlay, AirPlay 2 versus AirPlay respectively. Access to the Spotify service is on each of the competitors. The number of available streaming services varies for receivers, the Pioneer Elite SC-LX704 works with Deezer, TIDAL, Pandora, but the Pioneer SC-LX501 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 Elite SC-LX704 and the SC-LX501. Each of the devices can increase the resolution of the incoming video signal. Each of the participants of the comparison has a Dolby Vision.
The number of HDMI inputs/outputs varies depending on the receiver, the Elite SC-LX704 has 7/3, and the SC-LX501 has 7/2. HDMI Audio Return Channel is implemented in both devices. HDMI eARC is not supported by the Elite SC-LX704 and the SC-LX501. When comparing receivers, it becomes clear that each of the rivals can work with HDMI CEC. The Elite SC-LX704 has support for the standard HDCP 2.3, compared to the SC-LX501, which supports the standard HDCP 2.2. Like most receivers, our models have a built-in phono stage for connecting a vinyl player.
Unlike the Elite SC-LX704 where 3 Multi zones is provided, the SC-LX501 works with 2 Multi zones. There is an ECO mode in neither AV receiver. The Pioneer Elite SC-LX704 and 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.