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At US$2,569, this used Unison Research S6 sits just above the median of US$2,412 for recent comparable listings, making it a fair price compared to the obvious alternative of hunting for a similarly priced tube integrated with less pedigree. It falls comfortably between the 25th percentile (US$2,157) and 75th percentile (US$2,668), so you’re not getting a bargain, but you’re not overpaying either.
The S6 is well-regarded for its lush, Class-A single-ended triode sound using 6xEL34 valves, delivering 40 watts with a wide frequency response and a dual-mono build that enthusiasts love for its musicality and warmth. If this listing is from an original owner with no known issues and includes original accessories, it’s a solid buying opportunity for anyone seeking Italian tube charm without the new-unit cost of US$5,995 or more.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.
Unison Research, an Italian hi-fi icon, traces its roots to 1987, when it was founded in Treviso by Giovanni Maria Sacchetti, a visionary electronics engineer and music enthusiast born in 1945. Sacchetti, who balanced a career in teaching with amplifier design, assembled a team of dedicated audiophiles driven by a singular passion: delivering profound musical pleasure through superior sound. From its inception, the company emphasized handmade craftsmanship entirely within Italy, evolving under subsequent leadership like Giovanni Nasta while honoring Sacchetti's legacy of innovation in tube-based audio.
The brand excels in valve amplifiers, its core strength, with legendary models like the Triode 20—the first integrated amp Sacchetti designed—and the Simply Two, which sold over 30,000 units and propelled global acclaim. Early offerings included the Glowy preamp and Ruler power amp, pioneering designs such as the first stereo amplifier using the 845 triode. Today, Unison Research offers a focused lineup of preamplifiers, power amps, integrated amplifiers, and select speakers in partnership with Opera Loudspeakers, prioritizing pure analog warmth over digital peripherals like DACs or headphones.
Positioned as a high-end boutique leader, Unison Research reigns as Italy's top tube amplifier producer and ranks among Europe's elite ten. Audiophiles worldwide revere its products for their emotional depth, artisanal quality, and timeless appeal, cementing a niche among discerning buyers seeking authentic, soul-stirring hi-fi that transcends mere technical specs.
See all Unison Research listings on RADAR.
Hifitörget
Reverb
StereoNET
eBay UK
GB
audio-markt.de
Good
SoundTribe Asia
Dealer
Good
SG
