These are not the same size of amplifier: Buchardt I150 has roughly 2x the power of Cambridge Audio Evo 75. That is about 3dB, so it is a question of room size and how hard your speakers are to drive, not of one being the better amplifier.
| Area | Better | Why |
|---|
| Power | A | Buchardt I150 has more power - 150W against 75W into 8 ohms. That is about 3dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Buchardt I150 the better fit for a large room and a very large room, and Cambridge Audio Evo 75 for desk or near-field listening, a small room and a mid-size room. Match the amplifier to the room you actually have, not the one you want. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output nearly doubles (300W and 150W). |
| Built-in DAC | A | Both decode on board. Buchardt I150 goes higher - 394kHz against 384kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Streaming | B | Only Cambridge Audio Evo 75 has AirPlay 2, Chromecast and Roon. |
| Analogue inputs | evenly matched | The same number of line-level inputs (1). |
| Room to grow | evenly matched | The same expansion options on both. |
| Headphones | depends | Only Cambridge Audio Evo 75 has a headphone output. Worth something if you listen late, nothing if you never do. |
| Price | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | A | Buchardt I150 is the cheaper watt - about $17 per watt against $33. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Buchardt I150 B Cambridge Audio Evo 75
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?
Buchardt I150 has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. Start with the room. In a large or open-plan room, or with speakers that are hard to drive - low sensitivity, or an impedance that dips - Buchardt I150 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 75 watts is already more than most people ever use, and the extra 75 watts would be headroom you pay for and never hear - we rate Buchardt I150 poorly for near-field use for exactly that reason.
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.