Усилители мощности стерео — Unison Research Unico DM V2

The Unico DM v2 is the hybrid dual-mono power amplifier in the Unico range, made by an Italian company whose catalogue is built mainly around valve amplification. It is the first product in which the company introduced its A.S.H.A. technology, and the maker describes this solution as the foundation on which the new Unico series is being developed. The v2 succeeds the earlier Unico DM, which the company has since moved to its list of discontinued products.

Key specs that matter

Measured at 1 kHz and 1 percent THD, stereo output reaches 220 W per channel into 8 ohm, 340 W into 4 ohm and 370 W into 2 ohm, with a peak figure of 670 W into 2 ohm. Switched to bridged mono, the amplifier produces 650 W into either 8 or 4 ohm. Each channel draws on its own encapsulated toroidal transformer rated at 750 VA. Inputs comprise one RCA and one XLR socket, and a remote power-on input and output allow switching together with other components. The chassis measures 46 x 42 x 21 cm and weighs 33 kg.

Engineering and use context

Amplification is split into three stages, starting with a Class A valve stage using two ECC82, also known as 12AU7, from Gold Lion. A solid-state second stage then adapts the signal to the output section, which runs as a complementary push-pull circuit with three parallel pairs of MOSFETs. A.S.H.A. gives rise to a power-stage configuration the maker names Class A-AB, intended to combine Class A operation with the efficiency and reliability of Class AB. Because the two channels have separate supplies, bridged mono operation connects those supplies in parallel, turning the dual-mono layout into a single-channel amplifier with one larger power reservoir. A 15 mm thick aluminium block is milled to form the front panel, a 2 mm aluminium cover wraps around the whole unit, and wooden inserts refer back to the historic Unico logo. Two finishes are offered, Midnight Black and Velvet Gold.

Pairing

Bi-wiring is supported through 4+4 speaker terminals. Rising output into 4 and 2 ohm suits low-impedance loudspeakers that ask for current, and a second unit allows both to run as bridged monoblocks. The balanced and single-ended inputs accept a valve or transistor preamplifier, including the Unico line preamplifiers from the same series.

Alternatives

The Unison Research Unico DM is the earlier hybrid dual-mono stereo power amplifier with a Class A ECC82 input stage, rated at 160 W per channel into 8 ohm.