Two versions of the same amplifier rather than two different designs, so the question is not which is better built but which set of features you actually need - and what the difference costs.
| Area | Better | Why |
|---|
| Power | B | Devialet Astra has more power - 150W against 105W into 8 ohms. That is about 1.5dB, which is a small step in loudness but real headroom on peaks. |
| Room size | depends | We rate Devialet Expert 140 Pro the better fit for a small room, and Devialet Astra for a large room and a very large room. Match the amplifier to the room you actually have, not the one you want. |
| Built-in DAC | B | Both decode on board. Devialet Astra goes higher - 384kHz against 192kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Streaming | B | Only Devialet Astra has AirPlay 2 and Chromecast. |
| Analogue inputs | B | Devialet Astra takes more analogue sources - 2 against 1. |
| Room to grow | B | Only Devialet Astra offers preamp outputs - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Price | A | Devialet Expert 140 Pro costs less - $6,500 against $20,000 at list. |
| Watts per dollar | A | Devialet Expert 140 Pro is the cheaper watt - about $62 per watt against $133. 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 Devialet Astra
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 Astra measures better, Devialet Expert 140 Pro costs about 68% less. With most speakers in most rooms that gap is smaller in practice than it looks here. Think about the whole system: the roughly $13,500 saved by taking the cheaper one would buy better speakers or a subwoofer, which does more for the sound than the difference between two competent amplifiers.
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.