Интегральные усилители — Ayre Acoustics EX-8 2.0

The EX-8 2.0 is an integrated amplifier built by Ayre Acoustics in Colorado, designed as a modular unit that can be ordered analogue-only or with a range of digital input options fitted inside. The 2.0 version replaced the original EX-8 and adds a revised output stage and a buffer stage. US prices start at USD 6,450 for the analogue-only unit, with USD 7,450 for the Digital Base with S/PDIF and AES/EBU, USD 7,950 with USB, USD 8,150 with Ethernet and USD 8,350 fully loaded.

Key specs that matter

Continuous output is 100 W per channel into 8 ohm and 170 W into 4 ohm. Analogue sources connect via a single XLR input or either of two RCA inputs, with input impedance of 2 MOhm balanced and 1 MOhm unbalanced. Frequency range is quoted as DC to 250 kHz. There is a single pair of speaker terminals, plus, balanced and single-ended preamplifier outputs, two 3.5 mm balanced headphone sockets and one 6.3 mm single-ended socket, with headphone levels of 4.0 V RMS balanced and 2.0 V RMS single-ended. Power draw is 120 W at idle, or 60 W in a low-current mode. The case is 438 mm wide, 114 mm high and 330 mm deep and weighs 11 kg.

Engineering and use context

Operating in class AB, the amplifier uses a Double Diamond output stage, with two pairs of bipolar transistors joined at their emitters and bases, which Ayre states runs cooler and more efficiently than earlier designs. Gain stages use the EquiLock circuit, which ties two transistors together to act as a single device. Level adjustment happens in analogue circuitry yet can still be adjusted from Roon, and the same control sets both the speaker and headphone levels. The headphone section has its own Double Diamond output stage rather than taking its signal from the speaker outputs. In the digital hub version the board adds USB, AES/EBU, one coaxial S/PDIF, two Toslink and Ethernet inputs, using an ESS ES9038Q2M chip with a custom Ayre clock and a minimum phase digital filter. USB accepts PCM up to 24 bit and 384 kHz and DSD128 as DoP, and the other digital inputs take PCM up to 24 bit and 192 kHz with DSD64.

Pairing

Since banana plugs are not accepted, speaker cables should be terminated with spades or left bare. The preamplifier outputs make it possible to add an active subwoofer or bi-amp with an extra power amplifier, and the analogue-only version can later be expanded with the digital board.

Alternatives

The Ayre AX-5 Twenty is a bigger Ayre integrated model, rated at 125 W per channel into 8 ohm and 250 W into 4 ohm.