Предусилители — Ayre Accoustics KX-R TWENTY

Ayre Acoustics describes the KX-R Twenty stereo preamplifier as a complete redesign of the original KX-R that the company introduced in 2008. It handles source selection and volume only, with no phono stage or digital section, and its circuit is fully discrete and fully balanced, operating with zero feedback.

Key specs that matter

There are eight inputs in total, four balanced on XLR and four single-ended on RCA. On the output side the preamplifier provides two balanced main outputs plus two balanced tape outputs. The balanced input impedance is 2 megohm, and the balanced output impedance is 300 ohms. Its bandwidth is given as DC to 250 kHz. Power draw is 35 W in standby and normal use and 65 W while the remote control is active. The chassis is 438 mm wide, 292 mm deep and 95 mm high, and the unit weighs 18 kg.

Engineering and use context

Gain is adjusted by Ayre's Variable Gain Transimpedance circuit, which alters how much the gain stage amplifies instead of passing the signal through a separate attenuator, and it offers 60 steps of 1.0 dB each. The outputs are fed by a Diamond circuit of Ayre design, and EquiLock circuitry works on each active gain device. The AyreLock power supply uses discrete voltage regulation and, according to Ayre, more than twice the capacitance of the supply in the previous KX-R. Input ground switching isolates the grounds of the connected sources from one another. Front panel controls work on a fly-by-wire basis, and the preamplifier can be operated fully from its remote. A fluorescent display can be dimmed, and an Ayre Conditioner filter on the power inlet reduces radio frequency interference arriving through the mains. The case shares its width and height with the VX-R Twenty.

Pairing

With two balanced main outputs, the KX-R Twenty can supply two power amplifiers at once, or a single amplifier together with a powered subwoofer, provided those accept XLR connections. The VX-R Twenty stereo power amplifier from Ayre shares the fully balanced, zero-feedback approach. On the input side, the XLR inputs take balanced players and DACs, while the RCA inputs cover single-ended equipment.

Alternatives

The Ayre KX-5 Twenty is the smaller preamplifier in the series, with six inputs, a 46-step volume control in 1.5 dB increments and a 10.5 kg chassis.