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 | Yamaha A-S301 has more power - 60W against 35W into 8 ohms. That is about 2.3dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Yamaha A-S301 the better fit for a very large room, and Cambridge Audio AXA35 for desk or near-field listening. Match the amplifier to the room you actually have, not the one you want. |
| Speaker load rating | A | Yamaha A-S301 is rated down to 4 ohms against 8, so it is the safer partner for a low-impedance speaker. |
| Noise floor | A | Yamaha A-S301 is the quieter design on paper - 99dB against 82dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Yamaha A-S301 has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Analogue inputs | A | Yamaha A-S301 takes more analogue sources - 6 against 5. |
| Room to grow | A | Only Yamaha A-S301 offers preamp outputs - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Price | A | Yamaha A-S301 costs less - $350 against $399 at list. |
| Watts per dollar | A | Yamaha A-S301 is the cheaper watt - about $6 per watt against $11. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Yamaha A-S301 B Cambridge Audio AXA35
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?
Yamaha A-S301 is the easier recommendation: it leads on most of the measured areas and costs less. Take Cambridge Audio AXA35 if one of the "depends" rows above describes your system. 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 - Yamaha A-S301 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 35 watts is already more than most people ever use, and the extra 25 watts would be headroom you pay for and never hear. If you already own a DAC or a streamer, the built-in one is money you are paying twice for, and Cambridge Audio AXA35 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.