These are not the same size of amplifier: Naim Nova PE has roughly 6x the power of Pass Labs XA25. That is about 7.8dB, 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 | B | Naim Nova PE has more power - 150W against 25W into 8 ohms. That is about 7.8dB - 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 Pass Labs XA25 the better fit for desk or near-field listening, a small room and a mid-size room, and Naim Nova PE for a large room and a very large room. Match the amplifier to the room you actually have, not the one you want. |
| Built-in DAC | B | Naim Nova PE 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 (2). |
| Use with a TV | depends | Only Naim Nova PE 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 Nova PE has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier class | depends | Pass Labs XA25 is Class A and Naim Nova PE is Class D. Class A runs hot and is inefficient by design, in exchange for the simplest signal path; Class D runs cool and draws almost nothing at idle. Modern examples of both measure well - judge by the rest of the page. |
| Shelf space | depends | Naim Nova PE takes up about 39% less shelf area (1145cm² against 1892cm²), and it is 173mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | Pass Labs XA25 costs less - $5,665 against $9,999 at list. |
| Watts per dollar | B | Naim Nova PE is the cheaper watt - about $67 per watt against $227. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Pass Labs XA25 B Naim Nova PE
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: Naim Nova PE measures better, Pass Labs XA25 costs about 43% 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 - Naim Nova PE has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 25 watts is already more than most people ever use, and the extra 125 watts would be headroom you pay for and never hear - we rate Naim Nova PE poorly for near-field use for exactly that reason. If this sits under a television, Naim Nova PE is the one to buy - HDMI ARC means the TV remote controls the volume and there is no second box in the way.
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.