Different price classes - Marantz MM7025 costs roughly 3.3x what Yamaha R200A does. Expect it to lead on paper; the question is whether you will hear the difference through the speakers you own.
| Area | Better | Why |
|---|
| Power | B | Marantz MM7025 has more power - 140W against 100W into 8 ohms. That is about 1.5dB, which is a small step in loudness but real headroom on peaks. |
| Analogue inputs | A | Yamaha R200A takes more analogue sources - 3 against 2. |
| Price | A | Yamaha R200A costs less - $300 against $1,000 at list. |
| Watts per dollar | A | Yamaha R200A is the cheaper watt - about $3 per watt against $7. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Yamaha R200A B Marantz MM7025
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?
Yamaha R200A has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. Think about the whole system: the roughly $700 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.