No single best amplifier here. What decides it is what you have to drive, what you need to plug in, and how much of the system you want in one box.
| Area | Better | Why |
|---|
| Power | A | Accuphase E-3000 has more power - 100W against 80W into 8 ohms. That is about 1dB, which is a small step in loudness but real headroom on peaks. |
| 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. |
| 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. |
| Room to grow | A | Only Accuphase E-3000 offers a pre-out/main-in loop - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Price | B | Naim Uniti Nova costs less - $6,899 against $9,500 at list. |
A Accuphase E-3000 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?
Accuphase E-3000 is ahead, but on only 1 of the measured areas, and it costs about 38% more. That is a lot of money for a narrow margin - Naim Uniti Nova is the sensible buy unless a specific feature above decides it for you. 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 Accuphase E-3000 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.