Unico 90

Unico 90 is a class AB hybrid integrated amplifier with zero feedback, as the most precious valve amplifiers uses only two stages. The heart of the Unico 90 circuit is found in its hybrid structure. All of the gain, and subsequently the “character” of the amp, is determined by the only tube stage made with ECC83 and ECC 81in particular multiple-parallel-totem-pole.

The Unico 90 is a near-perfect integrated amplifier, employing as few active stages as possible to produce a clean musical signal that is true to the original source material. Where the more powerful flagship Unico 150 has three active stages, the Unico 90 boasts lower power specifications but only uses a two-stage circuit with zero global feedback.

The Unico 90 is an integrated amplifier designed to accommodate a variety of sources via its three RCA and two XLR pair inputs. It’s also designed to work in almost any application, with its fixed and variable RCA outputs as well as the bi-wirable speaker terminals. The large casework is built to the same exacting standards as previous Unico designs, but the Unico 90 borrows the same three-plate front fascia introduced with the Unico 150, which adds an aesthetic enhancement over its predecessors. Operation is simple and effortless via the large front-panel controls or the supplied RC2 system remote; but the minimalist exterior belies the high-end technology hidden within.

The whole pre-amplifier section of the Unico 90 is entirely passive. The ultra-smooth, ultra-silent ALPS volume dial is armoured at four points, allowing for even better channel separation when listening at high volumes. The input switching control decouples inactive source inputs, reducing cross-talk for optimal technical performance, and also employs miniature mechanical relays made to very fine tolerances for zero signal loss.

The sonic ability of the Unico 90 comes from its gain stage, which is controlled by the amplifier’s valve section. The valve complement is made up of ECC83 tubes in double-triode totem pole configuration and ECC81 in parallel totem pole. The result of the circuitry effectively delivers six triodes per-channel with perfectly measured gain, near-flat distortion and minimal output impedance; while also providing sufficient power for the gain stage to be coupled directly to the output power stage. Inside the output stage, three pairs of HEXFETs are used per-channel.

The Unico 90 is a dual-mono amplifier, and three pairs of thermo-stable Class AB HEXFETs are used per-channel to provide a powerful-yet-controlled 160W (4Ω) audio signal. Thanks to this design, the Unico 90 is able to work with a wide variety of modern loudspeakers, including many more demanding designs.

The complex circuitry and accurate scientific principles employed throughout the Unico 90 are complimented by the purpose-designed transformer that needs no further thermal compensation, reducing the need for another active stage that so many amplifiers require. Similarly, all the capacitors found throughout the electronic circuit are specially selected for their excellent performance at very high frequencies and innate ability to exhibit very low levels of loss.

The Unico 90 has been created out of a highly technical Research & Development process by Unison Research, with thousands of tests and numerous prototypes being auditioned before the finished article arrived. However, by continually putting the audio performance first, the superlative technical standards employed inside make the Unico 90 a true high-end offering with unrivalled cosmetic, scientific and musical appeal.

Key Features:

• Audiophile-grade integrated amplifier
• Output power 160 + 160W at 4Ω
• ECC83 (12AX7) valves used at input stage
• Additional balanced inputs (XLR)
• Subwoofer output
• Bi-wirable speaker outputs
• RC2 remote included

We do not recommend connecting this amplifier to a speaker with a minimum impedance less-than 2Ω.

User Reviews