These are not the same size of amplifier: Yamaha R-N800A has roughly 2x the power of Audiolab 6000A MKII. That is about 3dB, so it is a question of room size and how hard your speakers are to drive, not of one being the better amplifier.
| Area | Better | Why |
|---|
| Power | A | Yamaha R-N800A has more power - 100W against 50W into 8 ohms. That is about 3dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Built-in DAC | A | Both decode on board, but only Yamaha R-N800A handles DSD. |
| Streaming | evenly matched | Only Yamaha R-N800A has AirPlay 2. Neither list is longer in a way that matters - check the one service you actually pay for. |
| Analogue inputs | evenly matched | The same number of line-level inputs (3). |
| Room to grow | evenly matched | The same expansion options on both. |
| Shelf space | depends | Audiolab 6000A MKII takes up about 27% less shelf area (1328cm² against 1830cm²), and it is 122mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | Audiolab 6000A MKII costs less - $1,099 against $1,400 at list. |
| Watts per dollar | A | Yamaha R-N800A is the cheaper watt - about $14 per watt against $22. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Yamaha R-N800A B Audiolab 6000A MKII
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 R-N800A leads across most of the measured areas for a fairly modest premium, so it is the easier pick if the budget stretches. Audiolab 6000A MKII is the one to take if it does not. 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 - Yamaha R-N800A has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 50 watts is already more than most people ever use, and the extra 50 watts would be headroom you pay for and never hear.
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.