Unison Research S6 Integrated Amplifier

First, bass. We'll lead with it because it's the conversation starter every time someone listens to this amplifier for the first time. The S6 grips speakers with a control you don't expect from a pure tube integrated. When we ran it with our Aurai Z165 speakers, they played deep into the 30Hz range with speed and authority that should not be possible from a tube amplifier at this power level. This is no-joke, solid-state-like bass control in a tube amplifier chassis.

The midrange is everything the EL34 is famous for: dimensional, layered, present. Guitars and vocals have an intimacy that demands attention. On difficult recordings from the 1980s — the kind that expose midrange hardness immediately — the S6 is relaxed and honest. Nothing artificial is happening.

The highs extend naturally and smoothly without any sense of roll-off or protection. The S6 does not sacrifice the top end to protect the midrange. It doesn't need to.

The Construction

EL34 output tubes, point-to-point wiring throughout, zero global negative feedback. Handcrafted in Italy at the Unison Research factory.

Press Recognition

The Unison Research S6 has been reviewed by Stereophile, Hi-Fi+, and The Absolute Sound. Stereophile's Recommended Components listing and Hi-Fi+'s consistent coverage over the years reflect a product that has earned its reputation through performance rather than marketing.

Specifications

• Output tubes: EL34
• Wiring: Point-to-point
• Feedback: Zero global negative feedback
• Origin: Handcrafted in Italy

Authorized Unison Research dealer. Questions about how the S6 differs from the S6 Black Edition, or whether it's the right match for your speakers? Reach out.