One is a streaming all-in-one and the other is an amplifier. Judge them on how many boxes you want and what you already own, not on the spec sheet alone.
| Area | Better | Why |
|---|
| Power | B | Bluesound POWERNODE N331 has more power - 100W against 80W into 8 ohms. That is about 1dB, which is a small step in loudness but real headroom on peaks. |
| Noise floor | B | Bluesound POWERNODE N331 is the quieter design on paper - 102dB against 98dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | B | Both decode on board, but only Bluesound POWERNODE N331 handles DSD and MQA. |
| Streaming | B | Only Bluesound POWERNODE N331 has AirPlay 2, Roon and BluOS. |
| Analogue inputs | evenly matched | The same number of line-level inputs (2). |
| Phono stage | depends | NAD C 368 has a built-in phono stage (MM) and Bluesound POWERNODE N331 does not. Decisive if you own a turntable, completely irrelevant if you do not - and an outboard phono stage is easy to add later either way. |
| Use with a TV | depends | Only Bluesound POWERNODE N331 has HDMI eARC, 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 | evenly matched | The same expansion options on both. |
| Shelf space | depends | Bluesound POWERNODE N331 takes up about 77% less shelf area (418cm² against 1840cm²), and it is 233mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | Bluesound POWERNODE N331 costs less - $1,299 against $1,499 at list. |
| Watts per dollar | B | Bluesound POWERNODE N331 is the cheaper watt - about $13 per watt against $19. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A NAD C 368 B Bluesound POWERNODE N331
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?
Bluesound POWERNODE N331 is the easier recommendation: it leads on most of the measured areas and costs less. Take NAD C 368 if one of the "depends" rows above describes your system. If you play records, NAD C 368 saves you buying a phono stage; if you do not, ignore that row entirely. If this sits under a television, Bluesound POWERNODE N331 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.