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 | A | Arcam SA35 has more power - 120W against 80W into 8 ohms. That is about 1.8dB, which is a small step in loudness but real headroom on peaks. |
| Grip on hard loads | A | Arcam SA35 holds up better into a 4-ohm load: its output increases strongly to 200W, where the other increases strongly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | A | Arcam SA35 is the quieter design on paper - 110dB against 106dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Both decode on board. Arcam SA35 goes higher - 384kHz against 192kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Streaming | A | Only Arcam SA35 has AirPlay 2, Chromecast and Roon. |
| Use with a TV | depends | Only Arcam SA35 has HDMI, 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 | evenly matched | The same expansion options on both. |
| Headphones | depends | Only Arcam A15 has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier class | depends | Arcam SA35 is Class G and Arcam A15 is Class A/B. Class G/H switches its supply rails to cut the heat a Class A/B design wastes; Class A/B runs warm and is the long-established mainstream choice. Modern examples of both measure well - judge by the rest of the page. |
| Price | B | Arcam A15 costs less - $999 against $3,300 at list. |
| Watts per dollar | B | Arcam A15 is the cheaper watt - about $12 per watt against $28. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Arcam SA35 B Arcam A15
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: Arcam SA35 measures better, Arcam A15 costs about 70% less. With most speakers in most rooms that gap is smaller in practice than it looks here. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Arcam SA35 is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. If this sits under a television, Arcam SA35 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.