Unison Research Unico 90 Stereo Tube Hybrid Integrated Amplifier

The Unison Research Unico 90 is a dual-mono hybrid integrated amplifier that runs a pure Class A valve stage into a Hexfet output, delivering 100 watts per channel into 8 ohms with zero global feedback. Sitting just below the flagship Unico 150, it pairs valve musicality with the grip and reliability of MOSFET power in a purist, line-level design built in Italy.

Key Features of the Unison Research Unico 90

• Pure Class A valve stage: Six valves, two ECC83 and four ECC81 (three per channel), run the input and driver work in pure Class A before the output stage.
• Hexfet MOSFET output: A Class AB output stage with three complementary Hexfet pairs per channel delivers 100 watts into 8 ohms and 160 watts into 4 ohms.
• Zero global feedback: The two-stage circuit uses local feedback only, with no global negative feedback, for a more open and immediate presentation.
• Dual-mono construction: Left and right channels are built as mirror images for low crosstalk and strong stereo separation.
• Balanced and single-ended inputs: Six line inputs in total, including two transformer-coupled balanced XLR pairs and a fixed-gain bypass input.
• Built in Italy: Hand-assembled by ARIA with audiophile-grade capacitors, multi-voltage operation set for US 120V, and a remote control.

A Pure Class A Valve Stage and Hexfet Output

The Unico 90 runs valves where they shape the sound and MOSFETs where they drive the speakers. Its input and driver work is handled in a single pure Class A stage built from an ECC83 double-triode totem pole with a parallel ECC81 totem pole, which amplifies the signal and drives the power stage directly. From there a Class AB Hexfet output stage with three complementary pairs per channel takes over. The result is the warmth and texture of valves with the control and reliability of solid-state power.

100 Watts, Dual Mono, Zero Global Feedback

Rated at 100 watts per channel into 8 ohms and 160 watts into 4 ohms, the Unico 90 is built as a dual-mono design, so each channel runs its own amplification for low crosstalk and strong stereo imaging. It applies no global negative feedback, using only local feedback within the two-stage circuit, an approach that many listeners feel keeps the music more open and alive. Output resistance stays below 0.4 ohms across the audio band, so the amplifier keeps firm control of the loudspeaker.

Audiophile-Grade Components

Open the Unico 90 and the parts count tells the story: WIMA film capacitors through the signal path and Mundorf M-Cap polypropylene capacitors at key positions, mounted on a tidy dual-mono board. These are the kinds of components usually reserved for separates at higher prices, and they are a large part of why the amplifier sounds the way it does.

Balanced, Single-Ended, and Bypass Inputs

Connectivity runs to six line-level inputs: three unbalanced RCA, two transformer-coupled balanced XLR pairs, and one unbalanced bypass input. The bypass runs at fixed gain, so the Unico 90 can act as a power amplifier or drop into a home-theater system with the preamp section out of the path. Outputs include a tape loop and a volume-controlled subwoofer output, and each channel offers two pairs of binding posts for bi-wiring. There is no onboard phono stage, so vinyl listeners add an external phono preamplifier.

Built in Italy

Unison Research builds the Unico 90 in Italy through its ARIA workshop. At 20kg it is a serious piece of engineering, finished with a three-piece machined aluminum front panel in silver or black and a selectable mains transformer that ships set for US 120V operation. A remote control handles volume, and the soft-start circuit mutes the outputs briefly at power-on.

About Unison Research

Unison Research is an Italian manufacturer known for valve and hybrid amplifiers that put music first. The Unico line is its hybrid family, combining valve preamplification with solid-state output stages to make the valve sound practical for everyday systems and a wide range of loudspeakers. Each Unico model is built in Italy.

Explore the Unison Research Unico Line

The Unico 90 sits near the top of Unison Research's Unico hybrid integrated range, just below the flagship. The Unico Primo is the entry point, with the Unico Nuovo and the Unico Due stepping up through the line, the Due adding an onboard DAC. Above the 90, the Unico 150 uses a three-stage circuit for 150 watts per channel and the largest rooms.

The Listening Room Difference

We're a third-generation family business with a brick-and-mortar showroom in Chestertown, Maryland, and a reputation built on exceptional service and relentless passion for hifi. Whether you're visiting in person or ordering online, we bring decades of experience, personalized service, and honest guidance to every interaction. We don't just ship boxes. We help build systems, answer your questions like real humans, and make sure every detail of your setup is right, from the cables to the final connection. Our passion is helping you get the most out of your gear, with support that lasts well beyond the sale.

Unison Research Unico 90 Specifications