Siblings in Marantz's Model range, so they share a design and a house sound. It comes down to power, features and price.
| Area | Better | Why |
|---|
| Power | A | Marantz Model 30 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 Marantz Model 30 the better fit for a large room and a very large room, and Marantz Model 50 for a small room. Match the amplifier to the room you actually have, not the one you want. |
| Grip on hard loads | A | Marantz Model 30 holds up better into a 4-ohm load: its output nearly doubles to 200W, where the other increases modestly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | B | Marantz Model 50 is the quieter design on paper - 113dB against 88dB. Audible mainly with sensitive speakers in a quiet room. |
| Analogue inputs | A | Marantz Model 30 takes more analogue sources - 6 against 5. |
| Room to grow | evenly matched | The same expansion options on both. |
| Amplifier class | depends | Marantz Model 30 is Class D and Marantz Model 50 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. |
| Price | B | Marantz Model 50 costs less - $1,800 against $2,999 at list. |
A Marantz Model 30 B Marantz Model 50
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?
The usual trade-off: Marantz Model 30 measures better, Marantz Model 50 costs about 40% less. With most speakers in most rooms that gap is smaller in practice than it looks here. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Marantz Model 30 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 $1,199 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.