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, 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.