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 | Mark Levinson No.5802 has more power - 125W against 70W into 8 ohms. That is about 2.5dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Naim Uniti Star the better fit for a small room, and Mark Levinson No.5802 for a large room and a very large room. Match the amplifier to the room you actually have, not the one you want. |
| Speaker load rating | B | 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 | B | Both decode on board, but only Mark Levinson No.5802 handles MQA. |
| Streaming | A | Only Naim Uniti Star has AirPlay 2, Chromecast and Roon. |
| Room to grow | evenly matched | The same expansion options on both. |
| Built-in sources | depends | Naim Uniti Star has a CD player built in. That is one less box if you still play discs or listen to radio, and dead weight if you do not. |
| Shelf space | depends | Naim Uniti Star 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 | A | Naim Uniti Star costs less - $5,699 against $8,500 at list. |
A Naim Uniti Star B Mark Levinson No.5802
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.5802 measures better, Naim Uniti Star costs about 33% less. With most speakers in most rooms that gap is smaller in practice than it looks here. Start with the room. In a large or open-plan room, or with speakers that are hard to drive - low sensitivity, or an impedance that dips - Mark Levinson No.5802 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 70 watts is already more than most people ever use, and the extra 55 watts would be headroom you pay for and never hear - we rate Mark Levinson No.5802 poorly for near-field use for exactly that reason. Think about the whole system: the roughly $2,801 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.