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 - 70W against 80W into 8 ohms is under 1dB, which is not an audible difference in loudness. |
| 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. |
| Analogue inputs | A | PrimaLuna EVO 400 Integrated takes more analogue sources - 5 against 2. |
| Use with a TV | depends | Only Naim Uniti Nova 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 Nova has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier type | depends | PrimaLuna EVO 400 Integrated is Tube and Naim Uniti Nova 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. |
| Price | A | PrimaLuna EVO 400 Integrated costs less - $6,495 against $6,899 at list. |
A PrimaLuna EVO 400 Integrated 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?
Neither runs away with it - they trade advantages. Let the "depends" rows and the speakers you already own settle it. If this sits under a television, Naim Uniti Nova 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 400 Integrated 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.