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 | evenly matched | Effectively the same output - 200W against 165W into 8 ohms is under 1dB, which is not an audible difference in loudness. |
| Speaker load rating | B | Devialet Expert 220 Pro is rated down to 2 ohms against 4, so it is the safer partner for a low-impedance speaker. |
| Noise floor | B | Devialet Expert 220 Pro is the quieter design on paper - 130dB against 111dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | B | Devialet Expert 220 Pro has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Streaming | evenly matched | Only Devialet Expert 220 Pro has Roon. Neither list is longer in a way that matters - check the one service you actually pay for. |
| Analogue inputs | A | Marantz PM-10 takes more analogue sources - 5 against 2. |
| Room to grow | B | Only Devialet Expert 220 Pro offers preamp outputs - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Headphones | depends | Only Marantz PM-10 has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier class | depends | Marantz PM-10 is Class D and Devialet Expert 220 Pro is ADH (Analog Digital Hybrid). 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 | Devialet Expert 220 Pro takes up about 28% less shelf area (1521cm² against 2108cm²), and it is 80mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | Marantz PM-10 costs less - $8,999 against $10,000 at list. |
| Watts per dollar | A | Marantz PM-10 is the cheaper watt - about $45 per watt against $61. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Marantz PM-10 B Devialet Expert 220 Pro
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: Devialet Expert 220 Pro measures better, Marantz PM-10 costs about 10% less. With most speakers in most rooms that gap is smaller in practice than it looks here. If you already own a DAC or a streamer, the built-in one is money you are paying twice for, and Marantz PM-10 becomes the more rational buy.
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.