Unison Research Simply 845

23 watts. That's the number. If you're doing the math on how that compares to your speaker's sensitivity and wondering whether it's enough — that's the right question to ask. The honest answer is: for the right speakers, in the right room, with the right music, 23 watts from an 845 triode is more than enough. More than enough in a way that 100 watts of something lesser isn't.

Unison Research has been building 845 amplifiers since 1994 — the original Absolute 845 is widely regarded as one of the finest valve amplifiers ever built. The Simply 845 is the current expression of that lineage in an integrated amplifier that doesn't require a separate preamplifier or a corresponding budget for one.

The 845 Tube

The 845 is a directly-heated triode — the cathode is the filament itself rather than a separate heater element warming a coated cathode. This construction is associated with the purest possible electron flow and the lowest noise floor achievable in a power triode. It runs at high plate voltage, which requires transformers of genuine quality to handle correctly, and it produces its modest wattage with a linearity and harmonic structure that makes those watts sound like more than they measure.

Single-ended operation means no push-pull symmetry, no crossover distortion, and an output that consists purely of the 845's character — even-order harmonics, natural compression behavior, and a midrange presence that listeners describe as voices-in-the-room realistic.

The Construction

Point-to-point wiring throughout. Hand-wound output transformers — the component that makes or breaks a SET amplifier. No feedback. Handcrafted in Treviso, Italy at the Unison Research factory where they've been building amplifiers for 30 years.

Press Recognition

Unison Research has been reviewed by Hi-Fi+, Stereophile, and The Absolute Sound consistently over the years. The Simply 845 specifically has been praised for bringing 845 SET performance to a price point that was previously unreachable for the topology, while maintaining the house character that made Unison Research's 845 amplifiers famous.

Specifications

• Type: Single-ended triode integrated amplifier
• Output tube: 845 directly-heated triode
• Output power: 23 watts per channel
• Topology: Single-ended, no feedback, point-to-point wiring
• Output transformers: Hand-wound
• Origin: Handcrafted in Treviso, Italy

Authorized Unison Research dealer. If you want to talk through whether your speakers and room are a good match for the Simply 845, reach out — it's a conversation worth having before you buy.