UNISON RESEARCH S6 BLACK EDITION

The Unison S6 Black Edition is a premium tube integrated amplifier that combines technological innovation and artisanal design. Featuring Genalex Gold Lion KT77 tubes, the removal of the Auto-Bias system, and an independent power supply for each tube, it delivers natural, dynamic, and detailed sound. The elegant design and premium finishes make the S6 Black Edition a one-of-a-kind piece for high-fidelity enthusiasts.

Description

The Evolution of a Classic: Innovation and Tradition in the New Special Version

The new Unison S6 Black Edition celebrates Unison’s DNA, taking the iconic S6 to new levels of performance and design.

Unison Research, one of the world’s most renowned companies in the high-fidelity world, is synonymous with artisanal excellence, technological innovation, and a passion for music. Founded in Italy, Unison Research has successfully combined the tradition of tube construction with the most modern audio techniques, creating products that have become true legends in the world of high-fidelity.

The Black Edition line: Performance and style without compromise

The Black Edition is not simply a marketing operation, but a real review of technologies and materials, which translates into a substantial improvement in sound and technical performance. The Unison S6 Black Edition model, together with the other products in the line such as Simply Italy and Triode 25, represents the pinnacle of an evolutionary path that maintains the fundamental principles of the Unison Research philosophy: construction quality, sonic excellence and distinctive design.

The first feature that catches the eye in the Black Edition series is the new front panel in glossy lacquered wood, the black gun metallic finishes and the renewed graphics. Every detail is designed to give the product a luxurious and refined appearance, worthy of its class.

Genalex Gold Lion valves: The beating heart of the amplifier

The basis of the exceptional sound of the Unison S6 Black Edition is the exclusive use of Genalex Gold Lion valves. The tradition of Gold Lion tubes dates back to the 1950s, when only the finest tubes produced by M&O Valve Company could bear this legendary brand. Each Genalex Gold Lion tube is handpicked and tested to ensure maximum reliability and top-notch sonic performance.

The S6 Black Edition uses ECC83 and ECC82 tubes in its preamplifier. Known for their detailed sound and ability to create a wide soundstage, these tubes were chosen for their linearity and precision in sound reproduction. The power stages, on the other hand, use KT77 tubes instead of the more common EL34 tubes. This choice is no coincidence: the KT77 was developed as a replacement for the EL34, but with a more linear frequency response and greater three-dimensionality of sound.

The KT77 Gold Lion tubes, with their gold-plated pins and “Kinkless Tetrode” design, provide extremely natural sound reproduction, with deep bass, crystal-clear high-frequency extension and extraordinary resistance even in the most extreme conditions. Compared to EL34s, the KT77 offers a richer sound, without the compression typical of lower-class tubes.

Technological innovation: Goodbye to the Auto-Bias system

One of the main innovations introduced in the S6 Black Edition is the removal of the Auto-Bias system. Traditionally, the auto-bias is used in tube amplifiers to automatically adjust the operation of the tubes themselves, via a resistor and a bypass capacitor on the cathode. However, the use of these components inevitably introduces distortion and phase shifts, especially at low frequencies, which colors the sound and limits its accuracy.

In the S6 Black Edition, eliminating the Auto-Bias system has allowed us to remove the cathode capacitors, extending the frequency response and significantly improving the sound quality, especially in the low frequencies. Without the resistance of the auto-bias, the tube can make the most of the available power, leading to an increase of approximately 15% in the overall power of the amplifier.

This improvement translates into a more dynamic, faster and more detailed sound, with deep and controlled bass reproduction. The end result is an extremely natural and uncolored sound reproduction, which brings out every musical nuance.

Input selection and Return GND technology

Another innovative aspect of the S6 Black Edition is the input selection system based on relays with Return GND technology, derived from Unison Research's flagship models such as the Reference Pre and the Absolute. This system has been designed to minimize crosstalk and ensure perfect isolation between the various inputs, avoiding any interference or signal degradation.

Return GND technology requires that the unused inputs are closed on load resistors, so that the signal and its ground do not propagate inside the electronic board, thus minimizing interference and improving sound clarity. This system, together with the use of armored micro-relays with gold-plated silver contacts, guarantees precise and uncompromising input selection.

Separate and independent power supply for each tube

The power section of the S6 Black Edition has been completely redesigned to ensure maximum stability and reliability. Each valve is fed by a separate and independent line, minimising interference between the various stages and improving the overall sound quality.

To obtain an even more precise transient response, Unison Research has introduced the use of polypropylene capacitors alongside traditional electrolytic capacitors. This solution allows for an extremely linear frequency response and a higher speed of response to impulses, improving the dynamics and definition of the sound.

Stereo subwoofer output and digital connectivity

The S6 Black Edition is not only a classy valve amplifier, but it is also an extremely versatile device, able to adapt to the needs of modern audio sources. One of the main innovations is the introduction of a stereo subwoofer output at line level, not limited in band, which allows you to easily integrate a subwoofer into the system without compromising the sound quality.

The subwoofer output is taken directly from the amplifier output, thus maintaining the same sound timbre as the other channels, to ensure a coherent and harmonious reproduction of low frequencies. This makes the S6 Black Edition also ideal for multi-channel systems or for those who want even deeper and more precise bass reproduction.

In addition, the digital section of the S6 Black Edition is cutting-edge: there are three digital inputs (USB, optical and electrical SPDIF), which support resolutions up to 384 kHz and DSD 256. The digital conversion is entrusted to the prestigious Sabre ES908K2M chip, recognized as one of the best D/A converters on the market, capable of ensuring faithful and detailed reproduction even of high-resolution digital audio formats.

Design and finishes of the highest level

In addition to its technical and sound performance, the S6 Black Edition also stands out for its refined design and high-quality finishes. The front panel in glossy lacquered wood, with a piano finish, is the result of a long artisan process, which requires multiple steps to obtain a perfect result. This treatment not only enhances the beauty of the wood, but also guarantees long-lasting protection against scratches and external agents.

The black gun metal finishes, with a cataphoresis surface treatment, offer exceptional resistance to external agents and give the amplifier an elegant and contemporary look. Every detail of the S6 Black Edition is designed to reflect the obsessive care with which it was designed and manufactured, combining tradition and innovation in a single product.

TECHNICAL SPECIFICATIONS

Circuiting: Dual Mono for optimal channel separation.

Power tubes: 6x KT77 Genalex Gold Lion for a smooth and natural sound reproduction.

Signal tubes: ECC83 Genalex Gold Lion for a wide and detailed soundstage.

Power: 40W per channel in class A.

Cathode Capacitor Less technology: elimination of cathode capacitors for a more detailed and faster response.

Inputs: 4 RCA inputs.

Subwoofer output: Unfiltered stereo, obtained from the amplifier output.

Digital section: 3 inputs (USB 384, DSD 256, S/PDIF optical and electrical up to 192 kHz).

DAC converter: Sabre ES908K2M, for excellent conversion quality.

Dimensions: 35 x 22 x 50 cm.

Weight: 35 kg.

Design: Front panel in glossy lacquered wood, Black Gun metallic finishes and renewed graphics.