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 | A | Devialet Expert 140 Pro has more power - 105W against 80W into 8 ohms. That is about 1.2dB, which is a small step in loudness but real headroom on peaks. |
| Speaker load rating | A | Devialet Expert 140 Pro is rated down to 2 ohms against 4, so it is the safer partner for a low-impedance speaker. |
| Built-in DAC | B | Both decode on board. Naim Uniti Nova goes higher - 384kHz against 192kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Streaming | B | Only Naim Uniti Nova has AirPlay 2 and Chromecast. |
| Analogue inputs | B | Naim Uniti Nova takes more analogue sources - 2 against 1. |
| Phono stage | depends | Devialet Expert 140 Pro has a built-in phono stage (MM,MC) and Naim Uniti Nova 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 Uniti Nova offers preamp outputs - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Headphones | depends | Only Naim Uniti Nova has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier class | depends | Devialet Expert 140 Pro is ADH (Analog Digital Hybrid) and Naim Uniti Nova is Class A/B. Class A/B runs warm and is the long-established mainstream choice. Modern examples of both measure well - judge by the rest of the page. |
| Price | A | Devialet Expert 140 Pro costs less - $6,500 against $6,899 at list. |
| Watts per dollar | A | Devialet Expert 140 Pro is the cheaper watt - about $62 per watt against $86. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Devialet Expert 140 Pro B Naim Uniti Nova
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?
The usual trade-off: Naim Uniti Nova measures better, Devialet Expert 140 Pro costs about 6% less. With most speakers in most rooms that gap is smaller in practice than it looks here. If you play records, Devialet Expert 140 Pro 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.