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 72W into 8 ohms. That is about 1.4dB, which is a small step in loudness but real headroom on peaks. |
| Built-in DAC | B | Bluesound POWERNODE N331 has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Streaming | B | Only Bluesound POWERNODE N331 has AirPlay 2, Roon and BluOS. |
| Analogue inputs | A | Rega Elex-R takes more analogue sources - 4 against 2. |
| Phono stage | depends | Rega Elex-R 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. |
| Room to grow | evenly matched | The same expansion options on both. |
| Amplifier class | depends | Rega Elex-R is Class A/B and Bluesound POWERNODE N331 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. |
| Shelf space | depends | Bluesound POWERNODE N331 takes up about 70% less shelf area (418cm² against 1376cm²), and it is 130mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | Bluesound POWERNODE N331 costs less - $1,299 against $1,395 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 Rega Elex-R 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 has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. If you play records, Rega Elex-R saves you buying a phono stage; if you do not, ignore that row entirely. If you already own a DAC or a streamer, the built-in one is money you are paying twice for, and Rega Elex-R becomes the more rational buy.
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.