UNISON RESEARCH UNICO PRIMO

Hybrid integrated stereo amplifier

Phono stage optional euro 180,00

The Unico Primo is a stereo integrated amplifier that features a sophisticated hybrid design combining vacuum tubes and MOSFET technology. It is capable of delivering more than 80 watts RMS continuous power into 8 ohms with both channels driven. The project has been finely tuned to handle impulsive and non-correlated signals—those that more closely resemble real-world musical content—enabling the amplifier to exceed its nominal power rating and deliver impressively dynamic and lifelike sound performance.

The prototype’s fine-tuning phase involved countless hours of critical listening. Throughout this process, a wide variety of musical genres were evaluated, different loudspeakers were tested, and numerous experienced listeners participated in the evaluation. Every circuit parameter was revised. Through subtle design tweaks and careful component selection, the final version of the amplifier was refined to deliver both high-level technical performance and exceptional musicality.

Insights gained during the development of Unison Research’s Reference series power amplifiers inspired the engineering team to explore more deeply the sonic potential of the ECC83/12AX7 dual triode tube, especially in specific circuit topologies. This research laid the foundation for a new line of products aiming to combine the very best of the company’s heritage with the most compelling results from recent experiments.

The design of the Unico Primo draws inspiration from the acclaimed UnicoP—a model widely praised by critics and the market alike—and shares with it the use of a single ECC83 dual triode tube for signal processing.

The input and preamplification stages have been custom-designed for the ECC83/12AX7 tube, which offers distinct sonic characteristics compared to the previously used ECC82. The driver and output stages retain the proven solutions of the original Unico series, enhanced with refinements derived from the company’s subsequent design experience.

Special attention was also given to the power supply section. The amplifier features a 380 VA toroidal transformer and oversized filter capacitors, resulting in improved dynamics and stronger drive capability.

Positioned as the entry-level model in the Unison lineup, the Unico Primo is equipped with an active stereo line output with volume control, ideal for connecting to an active subwoofer. One of the line inputs can also be converted into a phono input by installing an optional RIAA preamplification and equalization board, making the unit adaptable for vinyl playback.

The amplifier is entirely hand-assembled at Unison Research’s Treviso facility with nearly artisanal care. The chassis, made of brushed black anodized aluminum, lends the Unico Primo an elegant and understated aesthetic. Structurally, the amplifier is built for rigidity and vibration isolation, aided by a three-point suspension system that ensures better performance by minimizing environmental interference.

The result is a compact amplifier that encapsulates all the passion, expertise, and technology that Unison Research typically invests in its flagship models. The Unico Primo is a perfect representation of Italian design and craftsmanship—elegant, refined, and musical.

Technical specifications:

• Output Power: >80 W RMS continuous into 8 Ω
• Output Stage: POWER MOSFET in complementary pair configuration
• Biasing: Dynamic Class A
• Input Stage: Triodes in Class A
• Tubes: 1 x ECC83 (12AX7)
• Input Sensitivity: 260 mV
• Input Impedance: 50 kΩ / 47 pF
• Frequency Response: -0.1 dB @ 10 Hz / -0.5 dB @ 100 kHz
• Signal-to-Noise Ratio (SNR): 90 dB
• Total Harmonic Distortion (THD): 0.15% @ 10 W, 1 kHz
• Negative Feedback Factor: 10 dB
• Damping Factor: >50
• Inputs: 5 RCA line inputs, 1 RCA tape input
• Outputs: 1 RCA tape output, 1 RCA subwoofer output
• Speaker Terminals: 4 + 4 for bi-wiring
• Remote Control: Volume, infrared (IR)
• Power Consumption: 380 W max
• Dimensions (W x D x H): 43.5 x 43 x 9.5 cm
• Net Weight: 14 kg