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 | Advance Paris X-i75 has more power - 75W against 50W into 8 ohms. That is about 1.8dB, which is a small step in loudness but real headroom on peaks. |
| Grip on hard loads | B | Advance Paris X-i75 holds up better into a 4-ohm load: its output increases modestly to 110W, where the other barely increases. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | evenly matched | Much the same signal-to-noise ratio (90dB vs 90dB). |
| Built-in DAC | A | Both decode on board. NAD C3030 goes higher - 384kHz against 192kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Room to grow | B | Only Advance Paris X-i75 offers preamp outputs and a pre-out/main-in loop - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Amplifier class | depends | NAD C3030 is Class D and Advance Paris X-i75 is Class AB-T. 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 | NAD C3030 takes up about 19% less shelf area (1208cm² against 1494cm²). |
| Price | A | NAD C3030 costs less - $1,199 against $1,299 at list. |
| Watts per dollar | B | Advance Paris X-i75 is the cheaper watt - about $17 per watt against $24. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A NAD C3030 B Advance Paris X-i75
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?
Advance Paris X-i75 leads across most of the measured areas for a fairly modest premium, so it is the easier pick if the budget stretches. NAD C3030 is the one to take if it does not. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Advance Paris X-i75 is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating.
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.