Предусилители — Unison Research Unico Pre v2

The Unico Pre v2 is a fully balanced hybrid preamplifier from Unison Research of Treviso, Italy, and the company calls it the new top preamplifier of its Unico series. It launched together with the Unico DM v2 power amplifier, and the pair introduced a redesigned look for the whole Unico family. Its fascia is cut from a solid 15 mm aluminium block and offered in Midnight Black or Velvet Gold, a 2 mm aluminium cover wraps over the top and sides, and wooden inserts recall the historic Unico logo. The Unison Research logo itself works as the power button.

Key specs that matter

Line inputs number three on RCA and three on XLR, along with a Line In and a phono socket that takes either cartridge type. Input impedance is 20 kohm on RCA and 57 kohm on XLR, and maximum input voltage is 2.58 V RMS on RCA and 5 V RMS on XLR. Gain is 20 dB through RCA and 15 dB through XLR. Maximum output voltage at 1% THD+N and 1 kHz reaches 8 V on RCA and 16 V on XLR, with output impedance of 770 ohm and 1,500 ohm respectively. Global feedback is 0 dB and power consumption is 50 VA. The case measures 45 x 43 x 14 cm and weighs 11 kg.

Engineering and use context

Unison Research redesigned the circuit around three stages while keeping its dual-mono topology. The first stage uses two ECC83, also sold as 12AX7, valves from Gold Lion and runs in Class A, and the following stages are solid state. Volume is set by an integrated circuit with precision resistors, which the maker chose for accurate level steps and channel balance, and it can be adjusted by infrared remote. The built-in DAC is based on the Sabre ES9018K2M chip with a balanced output architecture. Through the USB-B port it handles PCM at up to 384 kHz, native DSD up to 256x and DoP up to 128x, and two Toslink plus two S/PDIF coaxial inputs accept up to 192 kHz. The phono stage uses semi-passive RIAA equalisation, and load and gain for MM and MC are selected on the rear panel.

Pairing

Signal leaves through one XLR output plus a pair of RCA outputs that the maker earmarks for bi-amping, as well as a dual unfiltered subwoofer output and a Line Out. Line In and Line Out let an external audio processor or a recording device join the chain. A 12 V remote power-on output, on a 3.5 mm socket, switches on a power amplifier together with the preamplifier. The Unico DM v2, its launch partner, has a matching trigger input.

Alternatives

Outside the Unico series, Unison Research also builds the Reference Pre, a valve preamplifier.