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 | evenly matched | Effectively the same output - 50W against 50W into 8 ohms is under 1dB, which is not an audible difference in loudness. |
| Grip on hard loads | A | OSD Nero Stream ARC holds up better into a 4-ohm load: its output nearly doubles to 100W, where the other barely increases. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | A | OSD Nero Stream ARC is the quieter design on paper - 95dB against 90dB. 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. |
| Use with a TV | depends | Only OSD Nero Stream ARC has HDMI ARC, so the television can drive it directly and one remote controls the volume. If the system is for music only, this changes nothing. |
| Room to grow | B | Only Audioengine N22 G2 offers preamp outputs - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Headphones | depends | Only Audioengine N22 G2 has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier class | depends | OSD Nero Stream ARC is Class D and Audioengine N22 G2 is Class A/B. Class D runs cool and draws almost nothing at idle; Class A/B runs warm and is the long-established mainstream choice. Modern examples of both measure well - judge by the rest of the page. |
| Shelf space | depends | Audioengine N22 G2 takes up about 38% less shelf area (218cm² against 351cm²), and it is 26mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | OSD Nero Stream ARC costs less - $199 against $269 at list. |
| Watts per dollar | A | OSD Nero Stream ARC is the cheaper watt - about $4 per watt against $5. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A OSD Nero Stream ARC B Audioengine N22 G2
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?
OSD Nero Stream ARC is the easier recommendation: it leads on most of the measured areas and costs less. Take Audioengine N22 G2 if one of the "depends" rows above describes your system. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - OSD Nero Stream ARC is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. If this sits under a television, OSD Nero Stream ARC is the one to buy - HDMI ARC means the TV remote controls the volume and there is no second box in the way.
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.