Siblings in Rotel's A range, so they share a design and a house sound. It comes down to power, features and price.
| Area | Better | Why |
|---|
| Power | A | Rotel A11 MKII has more power - 50W against 30W into 8 ohms. That is about 2.2dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Noise floor | evenly matched | Much the same signal-to-noise ratio (90dB vs 90dB). |
| Built-in DAC | evenly matched | Both have a DAC on board with much the same capability. |
| Price | B | Rotel A8 costs less - $499 against $799 at list. |
A Rotel A11 MKII B Rotel A8
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?
Rotel A11 MKII is ahead, but on only 1 of the measured areas, and it costs about 60% more. That is a lot of money for a narrow margin - Rotel A8 is the sensible buy unless a specific feature above decides it for you. Start with the room. In a large or open-plan room, or with speakers that are hard to drive - low sensitivity, or an impedance that dips - Rotel A11 MKII has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 30 watts is already more than most people ever use, and the extra 20 watts would be headroom you pay for and never hear. Think about the whole system: the roughly $300 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.