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 | A | Mark Levinson No.5802 has more power - 125W against 80W into 8 ohms. That is about 1.9dB, which is a small step in loudness but real headroom on peaks. |
| Room size | depends | We rate Mark Levinson No.5802 the better fit for a large room and a very large room, and Naim Uniti Nova for a small room. Match the amplifier to the room you actually have, not the one you want. |
| Speaker load rating | A | Mark Levinson No.5802 is rated down to 2 ohms against 4, so it is the safer partner for a low-impedance speaker. |
| Built-in DAC | A | Both decode on board, but only Mark Levinson No.5802 handles MQA. |
| Streaming | B | Only Naim Uniti Nova has AirPlay 2, Chromecast and Roon. |
| Room to grow | evenly matched | The same expansion options on both. |
| Shelf space | depends | Naim Uniti Nova takes up about 44% less shelf area (1371cm² against 2454cm²), and it is 243mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | Naim Uniti Nova costs less - $6,899 against $8,500 at list. |
| Watts per dollar | A | Mark Levinson No.5802 is the cheaper watt - about $68 per watt against $86. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Mark Levinson No.5802 B Naim Uniti Nova
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?
Mark Levinson No.5802 leads across most of the measured areas for a fairly modest premium, so it is the easier pick if the budget stretches. Naim Uniti Nova is the one to take if it does not.
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.