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 | NAD C 368 BluOS-2i has more power - 80W against 50W into 8 ohms. That is about 2dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Audiolab 6000A Play the better fit for desk or near-field listening and a small room, and NAD C 368 BluOS-2i for a mid-size room, a large room and a very large room. Match the amplifier to the room you actually have, not the one you want. |
| Grip on hard loads | A | Audiolab 6000A Play holds up better into a 4-ohm load: its output increases strongly to 75W, where the other barely increases. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | B | NAD C 368 BluOS-2i is the quieter design on paper - 98dB against 76dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | evenly matched | Both have a DAC on board with much the same capability. |
| Streaming | B | Only Audiolab 6000A Play has DTS Play-Fi; only NAD C 368 BluOS-2i has AirPlay 2, Roon and BluOS. |
| Analogue inputs | A | Audiolab 6000A Play takes more analogue sources - 4 against 2. |
| Room to grow | A | Only Audiolab 6000A Play offers a pre-out/main-in loop - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Amplifier class | depends | Audiolab 6000A Play is Class A/B and NAD C 368 BluOS-2i is Class D. Class A/B runs warm and is the long-established mainstream choice; Class D runs cool and draws almost nothing at idle. Modern examples of both measure well - judge by the rest of the page. |
| Price | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | B | NAD C 368 BluOS-2i is the cheaper watt - about $22 per watt against $34. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Audiolab 6000A Play B NAD C 368 BluOS-2i
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?
NAD C 368 BluOS-2i has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Audiolab 6000A Play is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. 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 - NAD C 368 BluOS-2i 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 30 watts would be headroom you pay for and never hear - we rate NAD C 368 BluOS-2i poorly for near-field use for exactly that reason.
What a spec sheet cannot show: how either sounds with your speakers, how the interface feels 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.