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 | evenly matched | Effectively the same output - 60W against 50W into 8 ohms is under 1dB, which is not an audible difference in loudness. |
| Grip on hard loads | B | Denon PMA-900HNE holds up better into a 4-ohm load: its output increases strongly to 85W, where the other increases strongly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | evenly matched | Much the same signal-to-noise ratio (105dB vs 105dB). |
| Built-in DAC | A | Both decode on board. Cambridge Audio CXA61 goes higher - 384kHz against 192kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Streaming | B | Only Denon PMA-900HNE has AirPlay 2, Roon and HEOS. |
| Analogue inputs | A | Cambridge Audio CXA61 takes more analogue sources - 5 against 3. |
| Phono stage | depends | Denon PMA-900HNE has a built-in phono stage (MM,MC) and Cambridge Audio CXA61 does not. Decisive if you own a turntable, completely irrelevant if you do not - and an outboard phono stage is easy to add later either way. |
| Room to grow | evenly matched | The same expansion options on both. |
| Price | B | Denon PMA-900HNE costs less - $949 against $1,099 at list. |
A Cambridge Audio CXA61 B Denon PMA-900HNE
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?
Neither runs away with it - they trade advantages. Let the "depends" rows and the speakers you already own settle it. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Denon PMA-900HNE is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. If you play records, Denon PMA-900HNE saves you buying a phono stage; if you do not, ignore that row entirely.
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.