AV Processor/Receiver Yamaha RX-A4A Black

Yamaha RX-A4A: 7.2-channel AVENTAGE receiver with SURROUND:AI and a Qualcomm QCS407 processor

The RX-A4A is a 7.2-channel AV receiver from the AVENTAGE series, designed for home cinema, music playback and gaming alike. Signal processing is built around the Qualcomm QCS407 with 64-bit computation, which drives the SURROUND:AI function — it analyses the scene in real time and distinguishes dialogue, background music, ambient sounds and sound effects in order to assign each the optimum spatial effect. Decoding covers Dolby Atmos and DTS:X, including Dolby Atmos Height Virtualizer, Dolby Surround and DTS Neural:X.

The amplifier section delivers 110 W per channel (8 ohms, 20 Hz–20 kHz, 2 channels driven) and is based on a High Slew Rate Amplifier circuit, which more than doubles the slew rate while maintaining transmission stability — the benefit is most audible with high-resolution signals. Digital conversion is handled by the ESS SABRE ES9007S Premier Audio DAC (384 kHz/32-bit) with a dynamic range of up to 120 dB. The construction employs the A.R.T. Wedge (fifth foot) and an H-shaped cross frame, a symmetrical internal layout and shortened signal paths, damping vibrations from the transformer, the power transistors and the loudspeakers.

Adaptation to room acoustics is taken care of by YPAO-R.S.C. with multi-point measurement, angle measurement, 3D calibration and 64-bit precision EQ computation, which also optimises the parameters for SURROUND:AI, Dolby Atmos and DTS:X. CINEMA DSP HD3 with 24 programmes creates virtual rear channels from the front, centre and surround speakers and enables playback of up to 11.1 channels even in a 7.1 set-up (with front presence speakers). The result is stable source localisation, intelligible dialogue and a seamless transition between quiet and dynamic passages. The rear channels can be handled wirelessly via MusicCast 20 or MusicCast 50.

The video section offers 7 HDMI inputs / 3 outputs (HDCP 2.3) with 8K/60 Hz and 4K/120 Hz pass-through at 40 Gb/s, support for HDR10+, Dolby Vision, eARC and the gaming features ALLM and VRR. Network features include 2.4/5 GHz Wi-Fi, Bluetooth, AirPlay 2, Spotify Connect and MusicCast multiroom, playback of FLAC up to 384 kHz/24-bit, WAV/AIFF up to 384 kHz/32-bit and DSD up to 11.2 MHz. Also on board are a phono input for a turntable, a 7.2-channel pre-out, Zone2 including HDMI, Pure Direct and control via the MusicCast and AV Setup Guide apps.

Key features

• Power: 7.2 channels, 110 W per channel (8 Ω, 0.06% THD)
• Processor: Qualcomm QCS407 with SURROUND:AI and 64-bit processing
• Conversion: ESS SABRE ES9007S, 384 kHz/32-bit, 120 dB
• HDMI: 7 inputs / 3 outputs, 8K/60 Hz, 4K/120 Hz, VRR and ALLM
• Calibration: YPAO-R.S.C. with multi-point measurement and 3D EQ