Cyrus Mono X 300 review

Paired with the DAC XP+, Cyrus's Mono X300 is a nearly unbeatable preamp/power combination Tested at £2500

What Hi-Fi? Verdict

Exceptionally good. If fluidity and agility are your thing, there’s little better


  • +

    Impressive detail resolution

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    lack of harshness

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    explosive punch and dynamics


  • -

    Styling doesn’t make it look like £5000’s-worth of power amplifier

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.

Cyrus has a problem at the top end of the market.

As individual and unusual as the company’s long-running die-cast chassis is, it’s also small, light and plain – none of which appeal to a typical high-end buyer.

It’s understandable: you want to feel like you’ve got your money’s worth, and the best way of doing this is to make it big, heavy and expensively finished.

Using similar casework makes sense for brand and cost reasons, but it means the build of this £2550 monobloc seems no better than that of Cyrus’s £925 6XP integrated amp. Listen to it, though, and you’re in for a treat.

The Mono X 300 is the latest generation of the company’s top-end monobloc power amplifier.

While previous versions had been limited to 150W (into 8 ohms) output, this version increases that to 235W – deeply impressive for something so small that still using conventional linear power supplies and analogue circuitry.

The Mono X 300’s zero global feedback internals are a bit special.

Put simply, whatever happens at the output doesn’t affect the input, as it would in any traditional design. It’s a tricky circuit to create, and it gives this monobloc a combination of talents we rarely hear.

Scale and authority
Let’s get the negatives out of the way. If you value scale and authority above all else, you can do better. It’s not that the Mono X 300 is poor in these areas – its pretty good – but better can be bought for similar money.

However, when it comes to detail, transparency and agility, we think this new Mono is king at the price.

It’s massively revealing, uncovering fine detail where most rivals gloss things over, and organises every little bit with a stability that’s hard to better.

Whether you’re a fan of dense material like Mahler’s Symphony No. 10 or something simpler like Sam Cooke’s A Change is Gonna Come, the Mono X 300 takes it all in stride.

Alongside the muscle you could want, there’s a degree of subtlety you wouldn’t expect.

It’s organic without displaying even the tiniest degree of excess warmth. And that’s to say nothing of the class-leading speed and dynamic ability.

The Mono X 300 is a superstar here. Don’t buy another £5000 power amp until you hear this one. It’s that good.

Tested with Cyrus DAC XP+

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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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