Интегральные усилители — Yamaha A-S201

The Yamaha A-S201 is the entry model in the A-S stereo integrated amplifier series, which also includes the A-S301, A-S501 and A-S701. It is a purely analogue design with an MM phono stage, a remote control and outputs for two pairs of loudspeakers, aimed at simple two-channel systems built around CD, tuner and turntable sources.

Key specs that matter

Yamaha rates the A-S201 at 100 W per channel into 8 ohms (40 Hz to 20 kHz, 0.2% THD), with a maximum of 100 W per channel into 8 ohms at 1 kHz and 10% THD and 140 W per channel into 4 ohms at 1 kHz and 0.7% THD for Europe. Dynamic power per channel is 125 W into 8 ohms, 150 W into 6 ohms, 165 W into 4 ohms and 180 W into 2 ohms. Frequency response runs from 10 Hz to 100 kHz within 0.5 dB and 3 dB limits. Distortion from the phono MM input to the record output is 0.025% at 2 V from 20 Hz to 20 kHz. The CD input has a sensitivity of 500 mV at 47 kilohms and its noise figure is quoted as 100 dB. The chassis measures 435 x 141 x 333 mm and weighs 6.7 kg.

Engineering and use context

The circuit layout keeps signal paths short, and the power transformer sits close to the power amplifier section to cut losses and raise peak supply capacity. Signal ground and power supply ground meet at a single point to avoid mutual interference and improve the noise figure. A Pure Direct switch routes the signal past the bass, treble and balance controls and the back buffer amplifier while keeping full output available. Five inputs in total, one of them the MM phono input, make the unit the centre of a compact setup. In the Yamaha series comparison the A-S201 is the only model without digital inputs, a subwoofer output, a DC trigger output and ToP-ART construction, and it has no quoted damping factor. The front panel has a hairline finish, and a headphone jack sits alongside the controls.

Pairing

Large screw-type speaker terminals accept thick cables, and the speaker selector switches between system A, system B or both at once. Record players fitted with MM pickups plug straight into the rear phono socket. Auto power standby switches the amplifier off after 2, 4, 8 or 12 hours without use, or can be disabled, and standby consumption is 0.5 W.

Alternatives

The Yamaha A-S501 in the same series adds optical and coaxial digital inputs, a subwoofer output and a rated 85 W per channel RMS into 8 ohms.