One is a streaming all-in-one and the other is an amplifier. Judge them on how many boxes you want and what you already own, not on the spec sheet alone.
| Area | Better | Why |
|---|
| Power | A | Primare I25 Prisma has more power - 100W against 70W 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 Primare I25 Prisma the better fit for a large room and a very large room, and Denon PMA-1700NE for a small room. Match the amplifier to the room you actually have, not the one you want. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output nearly doubles (200W and 140W). |
| Noise floor | B | Denon PMA-1700NE is the quieter design on paper - 107dB against 100dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Both decode on board. Primare I25 Prisma goes higher - 768kHz against 384kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Streaming | A | Only Primare I25 Prisma has AirPlay 2, Chromecast and Roon. |
| Analogue inputs | A | Primare I25 Prisma takes more analogue sources - 5 against 3. |
| Phono stage | depends | Denon PMA-1700NE has a built-in phono stage (MM,MC) 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 | A | Only Primare I25 Prisma offers preamp outputs - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Headphones | depends | Only Denon PMA-1700NE has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier class | depends | Primare I25 Prisma is Class D and Denon PMA-1700NE is Class A/B. Class D runs cool and draws almost nothing at idle; 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 | Denon PMA-1700NE costs less - $2,099 against $4,495 at list. |
| Watts per dollar | B | Denon PMA-1700NE is the cheaper watt - about $30 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 Primare I25 Prisma B Denon PMA-1700NE
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: Primare I25 Prisma measures better, Denon PMA-1700NE costs about 53% less. With most speakers in most rooms that gap is smaller in practice than it looks here. If you play records, Denon PMA-1700NE saves you buying a phono stage; if you do not, ignore that row entirely. Think about the whole system: the roughly $2,396 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.