These are not the same size of amplifier: HiFi Rose RA280 has roughly 3.6x the power of Denon PMA-1700NE. That is about 5.5dB, 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 | HiFi Rose RA280 has more power - 250W against 70W into 8 ohms. That is about 5.5dB - a different class of amplifier rather than a bigger version of the same one, and far more than most rooms will ever ask for. |
| 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 barely increases. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | evenly matched | Much the same signal-to-noise ratio (109dB vs 107dB). |
| Built-in DAC | B | Denon PMA-1700NE has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Headphones | depends | Only Denon PMA-1700NE has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier class | depends | HiFi Rose RA280 is Class AD and Denon PMA-1700NE is Class A/B. 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 | HiFi Rose RA280 takes up about 16% less shelf area (1638cm² against 1949cm²), and it is 68mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | Denon PMA-1700NE costs less - $2,099 against $3,395 at list. |
| Watts per dollar | A | HiFi Rose RA280 is the cheaper watt - about $14 per watt against $30. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A HiFi Rose RA280 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. 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 - HiFi Rose RA280 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 70 watts is already more than most people ever use, and the extra 180 watts would be headroom you pay for and never hear.
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.