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 | NAD C 388 BluOS-2i has more power - 150W against 100W into 8 ohms. That is about 1.8dB, which is a small step in loudness but real headroom on peaks. |
| Room size | depends | We rate Cambridge EXA100 the better fit for desk or near-field listening, a small room and a mid-size room, and NAD C 388 BluOS-2i for a very large room. Match the amplifier to the room you actually have, not the one you want. |
| Grip on hard loads | A | Cambridge EXA100 holds up better into a 4-ohm load: its output increases strongly to 155W, where the other barely increases. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | B | NAD C 388 BluOS-2i is the quieter design on paper - 95dB against 91dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Both decode on board, but only Cambridge EXA100 handles DSD. |
| Streaming | B | Only NAD C 388 BluOS-2i has AirPlay 2 and BluOS. |
| Analogue inputs | A | Cambridge EXA100 takes more analogue sources - 5 against 2. |
| Phono stage | depends | NAD C 388 BluOS-2i has a built-in phono stage (MM) and Cambridge EXA100 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 EXA100 is Class A/B and NAD C 388 BluOS-2i 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 EXA100 takes up about 13% less shelf area (1595cm² against 1840cm²), and it is 53mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | B | NAD C 388 BluOS-2i is the cheaper watt - about $15 per watt against $22. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Cambridge EXA100 B NAD C 388 BluOS-2i
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?
NAD C 388 BluOS-2i 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 EXA100 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 388 BluOS-2i 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.