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.5805 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.5805 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.5805 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.5805 handles MQA. |
| Streaming | B | Only Naim Uniti Nova has AirPlay 2, Chromecast and Roon. |
| Analogue inputs | A | Mark Levinson No.5805 takes more analogue sources - 3 against 2. |
| Phono stage | depends | Mark Levinson No.5805 has a built-in phono stage (MM,MC) and Naim Uniti Nova 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. |
| 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 $10,500 at list. |
A Mark Levinson No.5805 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?
The usual trade-off: Mark Levinson No.5805 measures better, Naim Uniti Nova costs about 34% less. With most speakers in most rooms that gap is smaller in practice than it looks here. If you play records, Mark Levinson No.5805 saves you buying a phono stage; if you do not, ignore that row entirely. Think about the whole system: the roughly $3,601 saved by taking the cheaper one would buy better speakers or a subwoofer, which does more for the sound than the difference between two competent amplifiers.
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.