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 | B | Sony ES STR-AZ5000ES has more power - 120W against 80W into 8 ohms. That is about 1.8dB, which is a small step in loudness but real headroom on peaks. |
| Speaker load rating | B | Sony ES STR-AZ5000ES is rated down to 4 ohms against 8, so it is the safer partner for a low-impedance speaker. |
| Analogue inputs | A | ARCAM AVR11 takes more analogue sources - 6 against 4. |
| Room to grow | evenly matched | The same expansion options on both. |
| Price | B | Sony ES STR-AZ5000ES costs less - $2,798 against $3,050 at list. |
| Watts per dollar | B | Sony ES STR-AZ5000ES is the cheaper watt - about $23 per watt against $38. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A ARCAM AVR11 B Sony ES STR-AZ5000ES
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?
Sony ES STR-AZ5000ES has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is.
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.