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 | A | Hegel A200 has more power - 150W against 100W into 8 ohms. That is about 1.8dB, which is a small step in loudness but real headroom on peaks. |
| Noise floor | evenly matched | Much the same signal-to-noise ratio (100dB vs 100dB). |
| Built-in DAC | B | Primare I25 Prisma has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Analogue inputs | B | Primare I25 Prisma takes more analogue sources - 5 against 4. |
| Phono stage | depends | Hegel A200 has a built-in phono stage (MM, derived from the Hegel V10 phono stage) and Primare I25 Prisma 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. |
| Headphones | depends | Only Hegel A200 has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier class | depends | Hegel A200 is Class A/B and Primare I25 Prisma is Class D. Class A/B runs warm and is the long-established mainstream choice; Class D runs cool and draws almost nothing at idle. Modern examples of both measure well - judge by the rest of the page. |
| Price | A | Hegel A200 costs less - $3,995 against $4,495 at list. |
| Watts per dollar | A | Hegel A200 is the cheaper watt - about $27 per watt against $45. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Hegel A200 B Primare I25 Prisma
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?
Neither runs away with it - they trade advantages. Let the "depends" rows and the speakers you already own settle it. If you play records, Hegel A200 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 Hegel A200 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.