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 | evenly matched | Effectively the same output - 60W against 70W into 8 ohms is under 1dB, which is not an audible difference in loudness. |
| Room size | depends | We rate Primare I15 Prisma the better fit for desk or near-field listening and a small room, and Denon PMA-1700NE for a mid-size room, a large room and a very large room. Match the amplifier to the room you actually have, not the one you want. |
| Grip on hard loads | B | Denon PMA-1700NE holds up better into a 4-ohm load: its output nearly doubles to 140W, where the other increases strongly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | B | Denon PMA-1700NE is the quieter design on paper - 107dB against 97dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Both decode on board. Primare I15 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 I15 Prisma has AirPlay 2, Chromecast and Roon. |
| Analogue inputs | B | Denon PMA-1700NE takes more analogue sources - 3 against 1. |
| Phono stage | depends | Denon PMA-1700NE has a built-in phono stage (MM,MC) and Primare I15 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 I15 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 I15 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. |
| Shelf space | depends | Primare I15 Prisma takes up about 29% less shelf area (1387cm² against 1949cm²), and it is 55mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | evenly matched | Priced within a few per cent of each other. |
A Primare I15 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?
Neither runs away with it - they trade advantages. Let the "depends" rows and the speakers you already own settle it. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Denon PMA-1700NE is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. If you play records, Denon PMA-1700NE 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.