UNISON RESEARCH UNICO 150

Pre owned. In excellent condition. No visible signs of wear. Supplied with remote control, manual, and original packaging.

The Unison Unico 150 represents the flagship integrated amplifier of the Italian brand Unison Research and stands as a reference dual-mono hybrid design, engineered to deliver a balanced combination of tube refinement and transistor power. The unit delivers 150 W RMS into 8 ohms, rising to 220 W into 4 ohms, demonstrating excellent drive capability and precise control even with demanding or low-efficiency loudspeakers.

The design is based on a highly optimized three-stage architecture following a “less is more” philosophy, aimed at minimizing the number of signal stages in order to preserve integrity and transparency. The first two stages operate in pure Class A using vacuum tubes, with ECC83 triodes in a totem-pole configuration at the input stage and ECC81 triodes in the driver stage, ensuring low distortion, controlled impedance, and highly linear gain. This is followed by a MOSFET output stage in dual-mono Class A/B configuration with no global feedback, designed to provide high current delivery, wide dynamics, and excellent operational stability.

The preamplifier and power sections are directly coupled for each channel, contributing to overall signal coherence and a particularly smooth and natural reproduction. Volume control is handled by a high-quality passive ALPS potentiometer, while input selection is managed via shielded relays, solutions that help keep the signal path as clean as possible.

Power supply is provided by two large 400 VA toroidal transformers, mounted in a opposed and encapsulated configuration in the central section of the chassis, ensuring substantial energy reserves and stable performance even under demanding load conditions. The entire circuit is implemented on a single PCB, a choice that minimizes signal path length and optimizes overall layout, in line with the brand’s design philosophy.

From a construction standpoint, the Unico 150 uses carefully selected high-grade components, including polypropylene capacitors for coupling stages and Italian-made filter capacitors, supported by additional high-quality polypropylene filtering elements. The entire circuit is fully analog and designed and assembled in Italy, following a manufacturing tradition focused on quality, control, and in-house production.

Connectivity includes four RCA line inputs and two balanced XLR inputs, along with a dedicated subwoofer output and high-quality gold-plated speaker terminals designed for bi-wiring. The balanced input uses dedicated transformers to ensure true balanced transmission and galvanic isolation, further enhancing signal purity.

Aesthetically and mechanically, the Unico 150 features a solid and imposing build, weighing approximately 25 kg, with a highly rigid chassis made of brushed anodized aluminum. The front panel introduces a three-plate vertical design, with 15 mm thick aluminum sections that give the amplifier an elegant yet understated and modern appearance. Heat dissipation is managed by two large lateral aluminum heatsinks connected by a structural reinforcement bar, improving overall rigidity and ensuring efficient thermal management while keeping operating temperatures under control.

The user interface is arranged in a simple and intuitive layout, with two large aluminum knobs for volume and input selection, a central window housing the infrared receiver, and side LED indicators showing the active input. Operation is supported by a remote control, and the amplifier includes a brief warm-up phase during which the power LEDs flash, with a recommended stabilization time of around ten minutes before optimal performance is reached.

Overall, the Unico 150 stands as an amplifier capable of blending the musicality of tubes with the control and solidity of solid-state technology, delivering a natural, dynamic, and coherent sound that fully reflects the engineering and sonic philosophy of Unison Research.

Technical specifications:

• Power output: 150 + 150 W RMS into 8 Ω; 220 + 220 W RMS into 4 Ω
• Frequency response: -1 dB @ 12 Hz – 45 kHz; -3 dB @ 6 Hz – 80 kHz
• Input impedance: 24 kΩ // 100 pF
• Sensitivity: 860 mV RMS
• Input & gain stage: pure Class A with ECC83 tubes; dual totem-pole ECC81 stage
• Output stage: thermally stable Class A/B with complementary Hexfet devices; 4 pairs per channel
• Inputs: 6 line inputs; 3 unbalanced; 2 balanced; 1 unbalanced bypass
• Line outputs: 1 tape; 1 sub with volume control
• Speaker outputs: 4 + 4 for bi-wiring
• Global feedback: 0 dB
• Local feedback: 16 dB
• Total harmonic distortion (THD): < 0.15% @ 1 kHz, 1 W; < 0.25% @ 1 kHz, 10 W; < 0.35% @ 1 kHz, 100 W; < 0.9% from 20 Hz to 20 kHz, 150 W
• Output impedance: < 0.4 Ω, resistive across the entire audio band
• Dimensions: 43.5 x 44 x 18 cm (H)
• Weight: 25 kg