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 | B | Devialet Expert 220 Pro has more power - 165W against 110W into 8 ohms. That is about 1.8dB, which is a small step in loudness but real headroom on peaks. |
| Room size | depends | We rate Luxman L-507Z the better fit for desk or near-field listening, a small room and a mid-size room, and Devialet Expert 220 Pro for a very large room. Match the amplifier to the room you actually have, not the one you want. |
| 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 105dB. 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. |
| Analogue inputs | A | Luxman L-507Z takes more analogue sources - 5 against 2. |
| Room to grow | A | Only Luxman L-507Z offers a pre-out/main-in loop - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Headphones | depends | Only Luxman L-507Z has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier class | depends | Luxman L-507Z is Class A/B and Devialet Expert 220 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 | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | B | Devialet Expert 220 Pro is the cheaper watt - about $61 per watt against $95. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Luxman L-507Z 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?
Devialet Expert 220 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 already own a DAC or a streamer, the built-in one is money you are paying twice for, and Luxman L-507Z 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.