Unison Research Preludio review

Unusual looks, high price, low power output – things don't look great for the Preludio, until you hear the beautiful midrange and unbridled enthusiasm Tested at £2295.00

What Hi-Fi? Verdict

Valve amps might not be as popular as they once were, but the Preludio is a fantastic example of the genre


  • +

    Quirky appearance

  • +

    sweet sounding treble

  • +

    expressive and emotional midrange

  • +

    detailed across the board


  • -

    Fussy about speakers

  • -

    looks won’t impress everyone

Why you can trust What Hi-Fi? Our expert team reviews products in dedicated test rooms, to help you make the best choice for your budget. Find out more about how we test.

Locking eyes with a valve amp is a bit like seeing a friend's newborn baby for the first time: some people are smitten and can see a place for one in their life, while others scream and run to the nearest exit.

But, love them or hate them, there's a lot to be said in favour of valve amps, and in particular the Unison Research Preludio.

The mixture of stainless steel and striking cherry wood, the smooth control knobs and the side-mounted heatsinks give this amp plenty of character.

The Preludio only outputs 14W per channel, so you need to make sure its partnering speakers are compatible and can be driven to their full potential (ideally they should have a sensitivity rating of at least 90dB).

Listening to the Preludio from cold, the presentation is closed-in and stifled, but it's surprising how the soundstage opens up as the valves hit their optimum working temperature.

Bass notes to Jay-Z's Run This Town have a much more convincing kick to them and there's a real dynamism and newly injected freedom as far as the flow of the track is concerned.

Bags of character in the midrange
Rhianna's vocal on the track is sweet and refined, her distinctive tone oozing character. The sweet, smooth-sounding treble and midrange never gives even a hint of hardness.

This honesty and integrity gives the Preludio a real star quality. It's a remarkably easy listen, but not in a dull or forgettable way.

Play 160 BPM, and the Preludio allows the percussion to sparkle in a manner that comparable amps struggle to match.

Spin another classical track such as John Williams' Theme To Jurassic Park and the Preludio steps up to the plate once again, producing an intimate, emotive sound.

There's no doubt the Preludio sounds like a classy piece of kit, and it thoroughly deserves its five-star rating.

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What Hi-Fi?

What Hi-Fi?, founded in 1976, is the world's leading independent guide to buying and owning hi-fi and home entertainment products. Our comprehensive tests help you buy the very best for your money, with our advice sections giving you step-by-step information on how to get even more from your music and movies. Everything is tested by our dedicated team of in-house reviewers in our custom-built test rooms in London, Reading and Bath. Our coveted five-star rating and Awards are recognised all over the world as the ultimate seal of approval, so you can buy with absolute confidence.

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