These are not the same size of amplifier: Cambridge Audio Evo 150 has roughly 2.1x the power of Marantz Model 40n. That is about 3.3dB, 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 | B | Cambridge Audio Evo 150 has more power - 150W against 70W into 8 ohms. That is about 3.3dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Marantz Model 40n the better fit for desk or near-field listening, a small room and a mid-size room, and Cambridge Audio Evo 150 for a large room and a very large room. Match the amplifier to the room you actually have, not the one you want. |
| Grip on hard loads | B | Cambridge Audio Evo 150 holds up better into a 4-ohm load: its output increases strongly to 250W, where the other increases modestly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Built-in DAC | B | Both decode on board. Cambridge Audio Evo 150 goes higher - 384kHz against 192kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Streaming | evenly matched | Only Marantz Model 40n has HEOS; only Cambridge Audio Evo 150 has Chromecast. Neither list is longer in a way that matters - check the one service you actually pay for. |
| Analogue inputs | A | Marantz Model 40n takes more analogue sources - 3 against 2. |
| Room to grow | evenly matched | The same expansion options on both. |
| Amplifier class | depends | Marantz Model 40n is Class A/B and Cambridge Audio Evo 150 is Class D. Class A/B runs warm and is the long-established mainstream choice; Class D runs cool and draws almost nothing at idle. Modern examples of both measure well - judge by the rest of the page. |
| Shelf space | depends | Cambridge Audio Evo 150 takes up about 44% less shelf area (1190cm² against 2126cm²), and it is 109mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | Marantz Model 40n costs less - $2,499 against $3,249 at list. |
| Watts per dollar | B | Cambridge Audio Evo 150 is the cheaper watt - about $22 per watt against $36. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Marantz Model 40n 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 leads across most of the measured areas for a fairly modest premium, so it is the easier pick if the budget stretches. Marantz Model 40n is the one to take if it does not. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Cambridge Audio Evo 150 is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. 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 - Cambridge Audio Evo 150 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 70 watts is already more than most people ever use, and the extra 80 watts would be headroom you pay for and never hear - we rate Cambridge Audio Evo 150 poorly for near-field use for exactly that reason.
What a spec sheet cannot show: how either sounds with your speakers, how the interface feels 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.