These are not the same size of amplifier: HiFi Rose RA180 has roughly 5x the power of Naim Uniti Nova. That is about 7dB, so it is a question of room size and how hard your speakers are to drive, not of one being the better amplifier.
| Area | Better | Why |
|---|
| Power | A | HiFi Rose RA180 has more power - 400W against 80W into 8 ohms. That is about 7dB - a different class of amplifier rather than a bigger version of the same one, and far more than most rooms will ever ask for. |
| Room size | depends | We rate HiFi Rose RA180 the better fit for a large room and a very large room, and Naim Uniti Nova for desk or near-field listening, a small room and a mid-size room. Match the amplifier to the room you actually have, not the one you want. |
| Built-in DAC | B | Naim Uniti Nova has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Streaming | B | Only Naim Uniti Nova has AirPlay 2, Chromecast and Roon. |
| Analogue inputs | A | HiFi Rose RA180 takes more analogue sources - 4 against 2. |
| Phono stage | depends | HiFi Rose RA180 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. |
| Headphones | depends | Only Naim Uniti Nova has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier class | depends | HiFi Rose RA180 is Class AD and Naim Uniti Nova is Class A/B. Class A/B runs warm and is the long-established mainstream choice. Modern examples of both measure well - judge by the rest of the page. |
| Shelf space | depends | Naim Uniti Nova takes up about 28% less shelf area (1371cm² against 1909cm²), and it is 127mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | A | HiFi Rose RA180 is the cheaper watt - about $17 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 HiFi Rose RA180 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?
HiFi Rose RA180 has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. 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 - HiFi Rose RA180 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 80 watts is already more than most people ever use, and the extra 320 watts would be headroom you pay for and never hear - we rate HiFi Rose RA180 poorly for near-field use for exactly that reason. If you play records, HiFi Rose RA180 saves you buying a phono stage; if you do not, ignore that row entirely.
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.