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 | evenly matched | Effectively the same output - 50W against 60W into 8 ohms is under 1dB, which is not an audible difference in loudness. |
| Grip on hard loads | A | Denon PMA-900HNE holds up better into a 4-ohm load: its output increases strongly to 85W, where the other increases modestly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | B | Marantz PM7000N is the quieter design on paper - 115dB against 105dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Both decode on board, but only Denon PMA-900HNE handles DSD. |
| Streaming | evenly matched | The same streaming platforms and services on both. |
| Analogue inputs | evenly matched | The same number of line-level inputs (3). |
| Room to grow | evenly matched | The same expansion options on both. |
| Price | A | Denon PMA-900HNE costs less - $949 against $1,299 at list. |
A Denon PMA-900HNE B Marantz PM7000N
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?
Denon PMA-900HNE has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Denon PMA-900HNE is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. Think about the whole system: the roughly $350 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.