Unison Research Unico Primo Hybrid Integrated Stereo Amplifier at Vinyl Sound Buffalo, NY USA

The Unico Primo is a hybrid integrated stereo amplifier from Unison Research (Treviso, Italy), available at Vinyl Sound in Buffalo, NY, USA. Described by Zero Fidelity's Sean Fowler as "tonally fun... great spatial separation... the soundstage has depth and layering to it that's usually reserved for much more expensive components," and reviewed in full by Stereophile magazine, the Unico Primo represents the most accessible entry point into the Unico amplifier family. Using a single ECC83 tube in a triode Class A input stage feeding a Dynamic Class A MOSFET complementary output stage, it delivers more than 80 watts per channel at 8 ohms with a frequency response extending to -0.5 dB at 100 kHz. Five RCA line inputs, one tape input, a subwoofer output, IR remote volume control, and a signal-to-noise ratio of 90 dB make the Unico Primo a complete integrated amplifier solution for listeners entering the world of hybrid tube amplification.

Single-Tube Triode Class A Input and Dynamic Class A MOSFET Output

The Unico Primo's circuit topology is the foundational Unico hybrid architecture: one ECC83 double triode operating in Class A establishes the gain and tonal character of the entire amplifier, feeding a Dynamic Class A MOSFET complementary output stage that provides the power and current capability. The MOSFET output stage uses a complementary pair in Dynamic Class A polarization -- bias current adjusts dynamically with signal level to maintain Class A linearity in the operating range most commonly encountered during music playback. A 10 dB feedback factor provides frequency response control and damping, and the output stage's damping factor above 50 ensures bass definition and frequency response linearity with common loudspeaker impedance curves. THD is 0.15% at 10 W/1 kHz -- a figure competitive with many all-solid-state amplifiers at this output power level.

Connectivity and System Integration

Five RCA line inputs and one tape input provide comprehensive source connectivity for CD players, DACs, network streamers, and other line-level components, with the tape input adding recording loop functionality. An IR remote governs volume from the listening position, controlling the motorized volume potentiometer without the need to approach the amplifier. A dedicated subwoofer RCA output carries a full-range signal for powered bass supplement integration. Four pairs of loudspeaker binding posts (4+4) support bi-wired connections. At 17.1 x 16.9 x 3.7 inches and 31 lbs, the Unico Primo's low-profile chassis fits under standard-height equipment shelves with ease. A phono stage for MM or MC cartridges is available as an optional factory-installed internal option.

Key Features

• Zero Fidelity Critical Acclaim: Sean Fowler of Zero Fidelity praised the Unico Primo as "tonally fun" with "great spatial separation" and a "soundstage with depth and layering usually reserved for much more expensive components."
• Stereophile Reviewed: Full review by Stereophile magazine, the leading US audiophile publication, confirming the Unico Primo's position as one of the finest hybrid integrated amplifiers at its price.
• Single ECC83 Triode Class A Input: One 12AX7 double triode in pure Class A governs the Unico Primo's entire sonic character -- all gain and tonal identity is established in this single tube stage.
• Dynamic Class A MOSFET Output: Complementary MOSFET pair with dynamic bias management for Class A-like linearity across the normal listening power range.
• 80+ W/ch at 8 ohm: Sufficient power for a wide range of loudspeakers in small to medium rooms, with a damping factor above 50 for bass control.
• 90 dB Signal-to-Noise Ratio: Low noise floor preserves low-level musical detail in quiet passages.
• Optional Phono Stage: Factory-installable MM/MC phono stage for turntable integration without a separate phono preamplifier.
• Low-Profile Chassis: At 3.7 inches tall, the Unico Primo fits under standard equipment shelf heights.

Technical Specifications

Awards and Critical Recognition

• Zero Fidelity (Sean Fowler): "Tonally fun... Great spatial separation... the soundstage has depth and layering to it that's usually reserved for much more expensive components."
• Stereophile -- Full review published

Frequently Asked Questions

What is the Unison Research Unico Primo?

The Unison Research Unico Primo is a hybrid integrated stereo amplifier from Treviso, Italy, using a single ECC83 triode tube in a Class A input stage and a Dynamic Class A MOSFET complementary output stage producing more than 80 watts per channel at 8 ohms. It has five RCA line inputs, tape I/O, a subwoofer output, IR remote volume, a 90 dB SNR, and an optional factory-installed phono stage. It received a full review in Stereophile and was praised by Zero Fidelity for its soundstage depth and tonal character.

How does the Unico Primo compare to the Unison Research Unico Nuovo?

The Unico Primo uses a single ECC83 tube section in triode Class A and produces 80+ W/ch, while the Unico Nuovo uses a parallel ECC83 configuration (multiple tube sections in parallel) to produce 95 W/ch. Both use Dynamic Class A MOSFET output stages and 10 dB of feedback. The Unico Primo is lighter (31 lbs vs 16 kg) and lower-profile (3.7 inch vs 9.5 cm height), making it the physically more compact option. The Unico Nuovo's parallel tube input offers somewhat lower noise and higher current drive to the output stage, corresponding to its higher rated output power.

What is the role of the single ECC83 tube in the Unico Primo?

The single ECC83 (12AX7) double triode is responsible for all the gain in the Unico Primo's signal path. In pure Class A triode operation, the ECC83 amplifies the input signal with the harmonic character inherent to directly-heated and indirectly-heated triodes -- a gentle emphasis on second-harmonic content that contributes to the tonal warmth and three-dimensional imaging that Unico hybrid amplifiers are known for. The MOSFET output stage adds power and current but introduces no additional gain stage that could alter the character established by the tube. This direct tube-to-MOSFET architecture is the defining engineering choice of the entire Unico series.

Can the Unico Primo accommodate a phono stage for a turntable?

Yes. An optional factory-installed phono stage is available for the Unico Primo, accommodating both moving-magnet and moving-coil cartridges. When installed, one of the five RCA inputs is allocated to the phono stage. External phono preamps, including the Unison Research Simply Phono and Phono One, can also be connected to any of the line-level RCA inputs without the internal phono option.

Where can I buy the Unison Research Unico Primo in Buffalo, NY or the USA?

The Unison Research Unico Primo is available at Vinyl Sound in Buffalo, NY, USA. Vinyl Sound is an authorized Unison Research dealer serving western New York and the United States. Contact the Vinyl Sound team for current availability, phono stage option details, and in-store demonstration scheduling.