Unison Research Triode 25 Black Edition

Most tube amplifiers make you commit. You choose a topology — triode or pentode — and you live with its strengths and trade-offs. The Triode 25 Black Edition gives you both, switchable from the top panel, and the difference between them is real and audible enough to matter.

The Two Modes

In pentode mode, the amplifier delivers 50 watts per channel. The presentation is controlled, relatively neutral, and detailed — pentode's strength is power and bandwidth, and the Triode 25 uses it well for music that benefits from grip and authority. Use pentode for demanding loudspeakers or demanding listening levels.

In triode mode, the output drops to 25 watts and the character changes. The harmonic structure shifts toward the even-order presentation that triode operation produces — more dimensional, more liquid, more present in the midrange. What triode gives up in power and measured performance, it returns in musical engagement. The Triode 25 Black Edition was named for this mode. It's the reason the amplifier exists.

The Construction

EL34 output tubes — one of the great British output tube types, with a midrange character that has defined the sound of a generation of amplifiers from Mullard through to the present day. Zero global negative feedback in both modes. Handcrafted in Italy at the Unison Research factory.

Press Recognition

The Triode 25 Black Edition has been reviewed by Hi-Fi+, Positive Feedback, and Hifi News. Reviewers consistently highlighted the switching functionality as genuinely useful rather than a gimmick, and the triode mode specifically as delivering a quality of midrange presentation that competing amplifiers at similar prices don't match.

Specifications

• Output power: 50 watts per channel (pentode), 25 watts per channel (triode)
• Mode switching: Top-panel, user-accessible
• Output tubes: EL34
• Feedback: Zero global negative feedback
• Origin: Handcrafted in Italy

Authorized Unison Research dealer. Questions about speaker matching in triode mode, or how the Triode 25 compares to the Simply Italy? Reach out.