One is a streaming all-in-one and the other is an amplifier. Judge them on how many boxes you want and what you already own, not on the spec sheet alone.
| Area | Better | Why |
|---|
| Power | B | Marantz MODEL M1 has more power - 100W against 80W into 8 ohms. That is about 1dB, which is a small step in loudness but real headroom on peaks. |
| Room size | depends | We rate Cambridge CXA81 II the better fit for a small room, and Marantz MODEL M1 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 | A | Cambridge CXA81 II holds up better into a 4-ohm load: its output increases strongly to 120W, where the other increases modestly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Built-in DAC | A | Both decode on board, but only Cambridge CXA81 II handles DSD. |
| Streaming | B | Only Marantz MODEL M1 has AirPlay 2 and HEOS. |
| Analogue inputs | A | Cambridge CXA81 II takes more analogue sources - 5 against 3. |
| Use with a TV | depends | Only Marantz MODEL M1 has HDMI eARC, so the television can drive it directly and one remote controls the volume. If the system is for music only, this changes nothing. |
| Room to grow | A | Only Cambridge CXA81 II offers A/B speaker terminals - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Amplifier class | depends | Cambridge CXA81 II is Class A/B and Marantz MODEL M1 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 | Marantz MODEL M1 takes up about 65% less shelf area (552cm² against 1595cm²), and it is 117mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | Marantz MODEL M1 costs less - $1,000 against $1,199 at list. |
| Watts per dollar | B | Marantz MODEL M1 is the cheaper watt - about $10 per watt against $15. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Cambridge CXA81 II B Marantz MODEL M1
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?
The usual trade-off: Cambridge CXA81 II measures better, Marantz MODEL M1 costs about 17% less. With most speakers in most rooms that gap is smaller in practice than it looks here. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Cambridge CXA81 II is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. If this sits under a television, Marantz MODEL M1 is the one to buy - HDMI ARC means the TV remote controls the volume and there is no second box in the way.
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.