One is a streaming all-in-one and the other is an amplifier. Judge them on how many boxes you want and what you already own, not on the spec sheet alone.
| Area | Better | Why |
|---|
| Power | B | Yamaha A-S3200 has more power - 100W against 70W into 8 ohms. That is about 1.5dB, which is a small step in loudness but real headroom on peaks. |
| Room size | depends | We rate Naim Uniti Star the better fit for a small room, and Yamaha A-S3200 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 | A | Naim Uniti Star has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Streaming | A | Only Naim Uniti Star has AirPlay 2, Chromecast and Roon. |
| Analogue inputs | B | Yamaha A-S3200 takes more analogue sources - 7 against 1. |
| Phono stage | depends | Yamaha A-S3200 has a built-in phono stage (MM,MC) and Naim Uniti Star 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. |
| Built-in sources | depends | Naim Uniti Star has a CD player built in. That is one less box if you still play discs or listen to radio, and dead weight if you do not. |
| Shelf space | depends | Naim Uniti Star takes up about 36% less shelf area (1371cm² against 2136cm²), and it is 175mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | Naim Uniti Star costs less - $5,699 against $8,000 at list. |
A Naim Uniti Star B Yamaha A-S3200
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 you play records, Yamaha A-S3200 saves you buying a phono stage; if you do not, ignore that row entirely. If you already own a DAC or a streamer, the built-in one is money you are paying twice for, and Yamaha A-S3200 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.