Unison Research S6

Unison Research S6 Integrated Class A Tube Amplifier

The Unison Research S6 is a meticulously handcrafted integrated tube amplifier designed and built in Treviso, Italy. It operates in pure Class A and delivers 30 to 35 watts per channel using a single-ended, ultra-parallel output stage with three EL34 tubes per channel. Its topology includes two directly coupled triode preamp stages and a carefully engineered, hand-wound output transformer that offers extended frequency response and refined sonic performance. The power transformer is robustly designed to provide ample energy for demanding playback conditions. All internal components are selected for their musicality and reliability, with gold-plated inputs and outputs to ensure signal integrity over time.

The amplifier supports 4 and 8 ohm loudspeaker connections and features five line-level inputs, one tape output, and a biasing system that combines automatic regulation with user adjustment through a front-panel meter. Physically, the S6 is both functional and elegant, with non-magnetic stainless steel knobs, hand-finished wood inlays, and a ventilated wire grille that provides heat dissipation while showcasing the amplifier’s tube array. The chassis design reflects a deep commitment to aesthetic harmony and mechanical integrity.

From a sonic standpoint, the S6 is known for its rich tonal balance, exceptional midrange liquidity, and natural warmth, all achieved through minimal feedback and extensive listening tests during its development. It performs best with moderately sensitive loudspeakers and excels in reproducing acoustic instruments, vocals, and dynamic recordings with emotional engagement and spatial realism. The S6 continues Unison Research’s tradition of combining technical sophistication with Italian craftsmanship to deliver a truly musical listening experience.