These are not the same size of amplifier: Hegel H600 has roughly 2x the power of Devialet Astra. That is about 3.1dB, so it is a question of room size and how hard your speakers are to drive, not of one being the better amplifier.
| Area | Better | Why |
|---|
| Power | A | Hegel H600 has more power - 303W against 150W into 8 ohms. That is about 3.1dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Hegel H600 the better fit for a very large room, and Devialet Astra for desk or near-field listening, a small room and a mid-size room. Match the amplifier to the room you actually have, not the one you want. |
| Bass control | A | Hegel H600 has the higher damping factor (4000 vs 2000), which usually means a tighter grip on a woofer. Above about 100 the returns flatten out, so read this as a tendency rather than a ranking. |
| Built-in DAC | A | Both decode on board, but only Hegel H600 handles DSD and MQA. |
| Streaming | evenly matched | The same streaming platforms and services on both. |
| Analogue inputs | A | Hegel H600 takes more analogue sources - 4 against 2. |
| Phono stage | depends | Devialet Astra has a built-in phono stage (MM/MC with 13 equalization curves and adjustable cartridge loading) and Hegel H600 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 | evenly matched | The same expansion options on both. |
| Amplifier class | depends | Hegel H600 is Class A/B and Devialet Astra 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. |
| Shelf space | depends | Devialet Astra takes up about 22% less shelf area (1490cm² against 1914cm²), and it is 59mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | Hegel H600 costs less - $13,800 against $20,000 at list. |
| Watts per dollar | A | Hegel H600 is the cheaper watt - about $46 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 Hegel H600 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?
Hegel H600 is the easier recommendation: it leads on most of the measured areas and costs less. Take Devialet Astra if one of the "depends" rows above describes your system. Start with the room. In a large or open-plan room, or with speakers that are hard to drive - low sensitivity, or an impedance that dips - Hegel H600 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 150 watts is already more than most people ever use, and the extra 153 watts would be headroom you pay for and never hear - we rate Hegel H600 poorly for near-field use for exactly that reason. If you play records, Devialet Astra 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.