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 | evenly matched | Effectively the same output - 130W against 120W into 8 ohms is under 1dB, which is not an audible difference in loudness. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output increases strongly (200W and 200W). |
| Noise floor | evenly matched | Much the same signal-to-noise ratio (112dB vs 110dB). |
| Built-in DAC | B | 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 | evenly matched | The same streaming platforms and services on both. |
| Room to grow | evenly matched | The same expansion options on both. |
| Headphones | depends | Only JBL SA750 75th Anniversary Edition has a headphone output. Worth something if you listen late, nothing if you never do. |
| Price | A | JBL SA750 75th Anniversary Edition costs less - $3,000 against $3,300 at list. |
A JBL SA750 75th Anniversary Edition B Arcam SA35
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, JBL SA750 75th Anniversary Edition costs about 9% less. With most speakers in most rooms that gap is smaller in practice than it looks here.
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.