Интегральные усилители — Eleven Audio A390

The A390 is a compact stereo integrated amplifier from Eleven Audio, a company based in Taipei, Taiwan. It is built around the maker's Voltage and Current Isolated Amplify technology, known as VCIA, and follows a first watt approach that optimises the circuit for the lowest output levels. The case is half the width of a standard component, and the US launch price was USD 1,699, with a Japanese price of JPY 242,000 including tax.

Key specs that matter

Output is 39 W per channel into 8 ohm, with a maximum output current of 10 A. Inputs comprise two unbalanced RCA pairs at 15 kohm and one balanced XLR pair at 20 kohm, each accepting up to 12 V peak to peak, and there is one set of speaker terminals. Gain can be set to 23.5, 33.5 or 43.5 dB. Eleven Audio quotes a frequency response of 1 Hz to 110 kHz at -1 dB, 119 dB of signal-to-noise and a slew rate of 26 V per microsecond. Maximum power draw is 160 W. The case measures 32 x 21 x 7.5 cm, the body alone is 62 mm tall without feet, and the weight is 4.7 kg.

Engineering and use context

Inside are two fully separate mono block amplifier modules operating in class AB. In the VCIA layout each stage works purely as a voltage amplifier or purely as a current amplifier, so the two tasks do not interfere with each other, and the aim is lower distortion. The core of each channel uses more than 300 selected components, and the positions of the circuit zeros and poles were calculated with modern control theory. Level is set by an electronic volume control built on a resistive R-2R ladder. The sensitivity of each input can be adjusted, and the amplifier stores gain and volume settings separately for every source, so switching between inputs does not bring sudden level jumps. All functions run from the single volume knob, turned and pressed, or from the supplied infrared remote. A full protection circuit guards the amplifier and the loudspeakers.

Pairing

With 39 W into 8 ohm, the A390 matches bookshelf or floorstanding speakers whose efficiency is moderate or high, and the 10 A current limit gives headroom for larger models. The balanced input suits a DAC or streamer with XLR outputs, while the two RCA pairs handle further line sources such as a phono stage. The half-width case fits beside a matching DAC on a desk or a narrow shelf.

Alternatives

Eleven Audio offers no other integrated amplifier besides the A390, as its other amplifier, the Formula S, is designed for headphones.