UNISON RESEARCH UNICO 90

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

The Unison Unico 90 embodies the very essence of Unison Research’s design philosophy—a dual-mono integrated amplifier in Class AB that blends artisanal craftsmanship with modern engineering. Delivering 100 watts per channel into 8 ohms and 160 watts into 4 ohms, it stands out for its hybrid circuitry with zero global feedback, a choice aimed at preserving signal purity and the natural musical character of the sound. At its core lies a single valve stage using ECC83 tubes in a dual-triode totem configuration and ECC81 tubes in a parallel totem layout, achieving a harmonious gain structure and exceptionally low output impedance—an unmistakable hallmark of the Treviso-based manufacturer. The power section features three pairs of thermally stable HEXFET transistors per channel, ensuring energetic yet controlled performance, a design derived from experience with the flagship Unico 150.

The circuit design employs only two active stages, unlike the three found in the top model, pursuing structural simplicity to minimize distortion and maintain tonal transparency. The preamplifier section is entirely passive, integrating a low-noise ALPS potentiometer that provides precise volume control and optimal channel balance. Input selection is handled by miniature shielded mechanical relays placed near the connectors to reduce crosstalk and interference.

Like the rest of the Unico line, the Unico 90 integrates both preamp and power amp sections within a single chassis, minimizing signal path length and maximizing efficiency. Unison Research’s thirty years of experience allow the seamless combination of tube and solid-state technologies, merging the warmth and refinement of valves with the power and stability of transistors. Every component is carefully chosen: the printed circuit boards are made of fiberglass, and the two toroidal power transformers—one per channel—are encapsulated and shielded for stable, noise-free operation.

In terms of connectivity, the Unico 90 offers three gold-plated RCA line inputs, two balanced XLR pairs, and one unbalanced bypass input for multichannel system integration. It also features a line-level output for an active subwoofer and two sets of speaker terminals per channel, always active and connected in parallel to facilitate bi-wiring. The amplifier is fully analog, with no DAC, USB, network, or Bluetooth interface, designed to deliver uncompromising sonic purity. Its dual-mono layout ensures each channel benefits from an independent power supply, allowing it to drive virtually any modern loudspeaker with authority.

Visually, the Unico 90 echoes the refined style of its bigger sibling, the Unico 150, with a sandblasted aluminum front panel available in silver or black finish. Two large knobs dominate the front—one for input selection and one for volume control—flanked by rows of blue LEDs indicating the selected input and valve warm-up status. Operation can be managed either via the front controls or the included RC2 remote, crafted in wood with discreet buttons.

Every detail of the Unison Unico 90 reflects the artisanal philosophy and meticulous attention to quality that define Unison Research. Entirely designed and built at the company’s Treviso headquarters—from conception to final listening tests—this amplifier embodies the true spirit of Made in Italy: a perfect blend of elegance, technical precision, and passion for music that transforms every listening session into a vivid, authentic experience.

Technical Specifications:

• Power Output: 100+100 W RMS @ 8Ω; 160+160 W RMS @ 4Ω
• Frequency Response: -1 dB @ 12 Hz and 45 kHz; -3 dB
• Input Impedance: 21 kΩ // 300 pF
• Sensitivity: 860 mV RMS
• Input and Gain Stage: pure Class A with ECC83 tubes and dual totem-pole ECC81 configuration
• Output Stage: thermally stable Class AB with complementary HEXFETs (3 pairs per channel)
• Number of Stages: 2 – signal amplification and power amplification
• Inputs: 6 line – 3 unbalanced RCA; 2 balanced XLR; 1 unbalanced bypass
• Line Outputs: 1 tape; 1 sub (with volume control)
• Speaker Outputs: 4 + 4 terminals for bi-wiring
• Global Feedback: 0 dB
• Local Feedback: 0 dB
• THD: < 0.15% @ 1 kHz, 1 W; < 0.5% @ 1 kHz, 10 W
• Output Impedance: < 0.4 Ω, resistive across the entire audio range
• Power Consumption: 550 W (maximum output on 8 Ω load)
• Dimensions: 43.5 × 44 × 18 cm (W × D × H)
• Weight: 20 kg