A valve amplifier against a solid-state one. They are not really rivals: they differ in character, in what they will drive and in what owning them involves, so start there rather than with the watts.
| Area | Better | Why |
|---|
| Power | B | Cambridge Audio Evo 150 has more power - 150W against 100W into 8 ohms. That is about 1.8dB, which is a small step in loudness but real headroom on peaks. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output increases strongly (160W and 250W). |
| Built-in DAC | B | Cambridge Audio Evo 150 has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Streaming | B | Only Cambridge Audio Evo 150 has AirPlay 2, Chromecast and Roon. |
| Room to grow | B | Only Cambridge Audio Evo 150 offers preamp outputs - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Amplifier type | depends | McIntosh MA252 is Hybrid and Cambridge Audio Evo 150 is Solid State. Valve designs are usually warmer and softer at the limits and need their tubes replaced eventually; solid state is the lower-maintenance choice. This is a taste and ownership decision, not a quality one. |
| Price | B | Cambridge Audio Evo 150 costs less - $3,249 against $5,000 at list. |
| Watts per dollar | B | Cambridge Audio Evo 150 is the cheaper watt - about $22 per watt against $50. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A McIntosh MA252 B Cambridge Audio Evo 150
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both amplifiers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
Cambridge Audio Evo 150 is the easier recommendation: it leads on most of the measured areas and costs less. Take McIntosh MA252 if one of the "depends" rows above describes your system. If you already own a DAC or a streamer, the built-in one is money you are paying twice for, and McIntosh MA252 becomes the more rational buy. Think about the whole system: the roughly $1,751 saved by taking the cheaper one would buy better speakers or a subwoofer, which does more for the sound than the difference between two competent amplifiers.
What a spec sheet cannot show: how either sounds with your speakers, how the controls feel day to day, and what the app is like to live with - which is where most all-in-one amplifiers are actually won or lost. Power figures are the manufacturers' own and are not measured to a common standard, so treat small differences as noise. If you can hear both, that will tell you more than any row above.