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 | B | Marantz MODEL M1 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 NAD C 359S the better fit for a small room, and Marantz MODEL M1 for 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 | A | NAD C 359S holds up better into a 4-ohm load: its output increases strongly to 120W, where the other increases modestly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Built-in DAC | A | Both decode on board, but only NAD C 359S handles MQA. |
| Streaming | A | Only NAD C 359S has BluOS and Qobuz. |
| Analogue inputs | evenly matched | The same number of line-level inputs (3). |
| Phono stage | depends | NAD C 359S has a built-in phono stage (MM) and Marantz MODEL M1 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 | B | Only Marantz MODEL M1 offers preamp outputs - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Amplifier class | depends | NAD C 359S is Class A/B and Marantz MODEL M1 is Class D. Class A/B runs warm and is the long-established mainstream choice; Class D runs cool and draws almost nothing at idle. Modern examples of both measure well - judge by the rest of the page. |
| Shelf space | depends | Marantz MODEL M1 takes up about 68% less shelf area (552cm² against 1740cm²), and it is 147mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | Marantz MODEL M1 costs less - $1,000 against $1,299 at list. |
| Watts per dollar | B | Marantz MODEL M1 is the cheaper watt - about $10 per watt against $19. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A NAD C 359S B Marantz MODEL M1
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 - NAD C 359S is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. If you play records, NAD C 359S 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.