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 | A | Michi X3 Series 2 has more power - 235W against 150W into 8 ohms. That is about 1.9dB, which is a small step in loudness but real headroom on peaks. |
| Grip on hard loads | B | Naim Nova PE holds up better into a 4-ohm load: its output increases strongly to 250W, where the other increases modestly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Built-in DAC | A | Both decode on board, but only Michi X3 Series 2 handles MQA. |
| Streaming | evenly matched | The same streaming platforms and services on both. |
| Analogue inputs | A | Michi X3 Series 2 takes more analogue sources - 5 against 2. |
| Phono stage | depends | Michi X3 Series 2 has a built-in phono stage (MM) and Naim Nova PE 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. |
| Use with a TV | depends | Only Naim Nova PE has HDMI ARC, so the television can drive it directly and one remote controls the volume. If the system is for music only, this changes nothing. |
| Room to grow | evenly matched | The same expansion options on both. |
| Amplifier class | depends | Michi X3 Series 2 is Class A/B and Naim Nova PE 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 Nova PE takes up about 48% less shelf area (1145cm² against 2192cm²), and it is 187mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | Michi X3 Series 2 costs less - $7,499 against $9,999 at list. |
| Watts per dollar | A | Michi X3 Series 2 is the cheaper watt - about $32 per watt against $67. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Michi X3 Series 2 B Naim Nova PE
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?
Michi X3 Series 2 is the easier recommendation: it leads on most of the measured areas and costs less. Take Naim Nova PE if one of the "depends" rows above describes your system. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Naim Nova PE is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. If you play records, Michi X3 Series 2 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.