Усилители мощности стерео — Yamaha XDA-QS5400RK

The Yamaha XDA-QS5400RK, called the QS or Quad Streamer, is a MusicCast multi-room streaming amplifier built for custom integration of whole home audio systems. It streams four zones of audio and drives eight amplifier channels from a 1U-high, rack-width enclosure, and it links with Yamaha AV receivers, sound bars and Hi-Fi components over Ethernet.

Key specs that matter

The QS uses Class D amplification, arranged as four stereo pairs, each assignable to any zone. At 1 kHz and 0.9% THD, both channels of a pair deliver 50 W into 8 ohms and 90 W into 4 ohms, or 100 W bridged into 8 ohms. A single driven channel reaches 50 W, 100 W and 200 W bridged, and maximum effective output at 10% THD is 65 W into 8 ohms, 130 W into 4 ohms and 260 W bridged. Minimum speaker load is 4 ohms. Speaker THD is 0.04% at 25 W into 8 ohms from 20 Hz to 20 kHz, and frequency response spans 10 Hz to 22 kHz at minus 3 dB. Signal-to-noise ratio is 114 dB at the preout from network or USB sources and 106 dB at the speaker outputs, while preout THD is 0.005% at 1 V. The preouts deliver 2 V rated and 4 V maximum from a 470 ohm output impedance. Gain is 25.8 dB and input sensitivity is 150 mV for 1 W into 8 ohms. On a table the unit measures 437 x 46 x 443 mm, and it weighs 6.3 kg.

Engineering and use context

Connections include four Euroblock speaker terminals, four preouts, two Ethernet ports, four USB inputs, RCA cut-in and AUX inputs with through outputs, four trigger outputs, remote in and out, and four chime circuits. The network section plays MP3, WMA, AAC and ALAC files up to 96 kHz and WAV, FLAC and AIFF up to 192 kHz at 24 bit, and it supports AirPlay. Each zone offers bass, mid and treble adjustment of plus or minus 6 dB in 0.5 dB steps at 350 Hz, 1.1 kHz and 3.5 kHz, plus bass extension, direct mode, a mono downmix option and volume adaptive EQ. Yamaha cites a ground loop and hum-free circuit design. Several QS units together expand the system to 32 zones, with linked groups of up to 20 zones each. IP control from third-party systems is supported, and removable rack ears and a faceplate come in the box. Power consumption is 130 W.

Pairing

The four zone preouts let the QS feed the companion XDA-AMP5400RK for more power or wider speaker coverage, or drive powered subwoofers and subwoofer amplifiers. A MusicCast receiver, sound bar or turntable on the network can supply TV or vinyl audio to any zone.

Alternatives

The Yamaha XDA-AMP5400RK is an eight-channel multi-room amplifier without the streaming section, fed through four RCA inputs.