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 | evenly matched | Effectively the same output - 90W against 105W into 8 ohms is under 1dB, which is not an audible difference in loudness. |
| Speaker load rating | B | 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 | Devialet Expert 140 Pro has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Analogue inputs | A | Accuphase E-280 takes more analogue sources - 5 against 1. |
| Phono stage | depends | Devialet Expert 140 Pro has a built-in phono stage (MM,MC) and Accuphase E-280 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. |
| Headphones | depends | Only Accuphase E-280 has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier class | depends | Accuphase E-280 is Class A/B and Devialet Expert 140 Pro is ADH (Analog Digital Hybrid). 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 | B | Devialet Expert 140 Pro costs less - $6,500 against $6,995 at list. |
| Watts per dollar | B | Devialet Expert 140 Pro is the cheaper watt - about $62 per watt against $78. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Accuphase E-280 B Devialet Expert 140 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?
Devialet Expert 140 Pro has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. If you play records, Devialet Expert 140 Pro saves you buying a phono stage; if you do not, ignore that row entirely. If you already own a DAC or a streamer, the built-in one is money you are paying twice for, and Accuphase E-280 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.