A valve amplifier against a solid-state one. They are not really rivals: they differ in character, in what they will drive and in what owning them involves, so start there rather than with the watts.
| Area | Better | Why |
|---|
| Power | evenly matched | Effectively the same output - 44W against 40W into 8 ohms is under 1dB, which is not an audible difference in loudness. |
| Room size | depends | We rate PrimaLuna EVO 200 Power the better fit for a very large room, and Naim Uniti Atom for desk or near-field listening. Match the amplifier to the room you actually have, not the one you want. |
| Built-in DAC | B | Naim Uniti Atom has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Analogue inputs | evenly matched | The same number of line-level inputs (1). |
| Use with a TV | depends | Only Naim Uniti Atom has HDMI ARC, so the television can drive it directly and one remote controls the volume. If the system is for music only, this changes nothing. |
| Headphones | depends | Only Naim Uniti Atom has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier type | depends | PrimaLuna EVO 200 Power is Tube and Naim Uniti Atom is Solid State. Valve designs are usually warmer and softer at the limits and need their tubes replaced eventually; solid state is the lower-maintenance choice. This is a taste and ownership decision, not a quality one. |
| Shelf space | depends | Naim Uniti Atom takes up about 47% less shelf area (781cm² against 1477cm²), and it is 88mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | evenly matched | Priced within a few per cent of each other. |
A PrimaLuna EVO 200 Power B Naim Uniti Atom
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?
Naim Uniti Atom has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. If this sits under a television, Naim Uniti Atom is the one to buy - HDMI ARC means the TV remote controls the volume and there is no second box in the way. If you already own a DAC or a streamer, the built-in one is money you are paying twice for, and PrimaLuna EVO 200 Power 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.