No single best amplifier here. What decides it is what you have to drive, what you need to plug in, and how much of the system you want in one box.
| Area | Better | Why |
|---|
| Power | B | NAD C 379 has more power - 80W against 60W into 8 ohms. That is about 1.2dB, which is a small step in loudness but real headroom on peaks. |
| Grip on hard loads | A | Cambridge Audio CXA61 holds up better into a 4-ohm load: its output increases strongly to 90W, where the other barely increases. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | A | Cambridge Audio CXA61 is the quieter design on paper - 105dB against 95dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Both decode on board, but only Cambridge Audio CXA61 handles DSD. |
| Phono stage | depends | NAD C 379 has a built-in phono stage 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. |
| Amplifier class | depends | Cambridge Audio CXA61 is Class A/B and NAD C 379 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. |
| Price | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | B | NAD C 379 is the cheaper watt - about $14 per watt against $18. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Cambridge Audio CXA61 B NAD C 379
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 CXA61 has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Cambridge Audio CXA61 is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. If you play records, NAD C 379 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.