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 - 70W against 70W into 8 ohms is under 1dB, which is not an audible difference in loudness. |
| 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 modestly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | evenly matched | Much the same signal-to-noise ratio (106dB vs 107dB). |
| Built-in DAC | B | Both decode on board. Denon PMA-1700NE goes higher - 384kHz against 192kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Streaming | A | Only Marantz Model 40n has AirPlay 2, Roon and HEOS. |
| Analogue inputs | evenly matched | The same number of line-level inputs (3). |
| Room to grow | A | Only Marantz Model 40n offers preamp outputs - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Price | B | Denon PMA-1700NE costs less - $2,099 against $2,499 at list. |
A Marantz Model 40n 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.
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.