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 | Naim CI-Uniti 102 has more power - 150W against 110W into 8 ohms. That is about 1.3dB, which is a small step in loudness but real headroom on peaks. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output increases strongly (180W and 260W). |
| Noise floor | B | Naim CI-Uniti 102 is the quieter design on paper - 110dB against 104dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Both decode on board. Onkyo Icon A-50 goes higher - 768kHz against 384kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Streaming | evenly matched | The same streaming platforms and services on both. |
| Phono stage | depends | Onkyo Icon A-50 has a built-in phono stage and Naim CI-Uniti 102 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 | B | Only Naim CI-Uniti 102 offers a subwoofer output - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Headphones | depends | Only Onkyo Icon A-50 has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier class | depends | Onkyo Icon A-50 is Class A/B and Naim CI-Uniti 102 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 | Naim CI-Uniti 102 takes up about 45% less shelf area (900cm² against 1636cm²), and it is 76mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | Naim CI-Uniti 102 costs less - $1,499 against $1,600 at list. |
| Watts per dollar | B | Naim CI-Uniti 102 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 Onkyo Icon A-50 B Naim CI-Uniti 102
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?
Naim CI-Uniti 102 has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. If you play records, Onkyo Icon A-50 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.