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 | JBL SA750 75th Anniversary Edition has more power - 130W against 90W into 8 ohms. That is about 1.6dB, which is a small step in loudness but real headroom on peaks. |
| Room size | depends | We rate JBL SA750 75th Anniversary Edition the better fit for a large room and a very large room, and Yamaha A-S1200 for a small room. Match the amplifier to the room you actually have, not the one you want. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output increases strongly (200W and 150W). |
| Noise floor | evenly matched | Much the same signal-to-noise ratio (112dB vs 110dB). |
| Built-in DAC | A | JBL SA750 75th Anniversary Edition has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Streaming | A | Only JBL SA750 75th Anniversary Edition has AirPlay 2, Chromecast and Roon. |
| Analogue inputs | B | Yamaha A-S1200 takes more analogue sources - 6 against 4. |
| Room to grow | evenly matched | The same expansion options on both. |
| Amplifier class | depends | JBL SA750 75th Anniversary Edition is Class G and Yamaha A-S1200 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. |
| Shelf space | depends | JBL SA750 75th Anniversary Edition takes up about 19% less shelf area (1718cm² against 2123cm²), and it is 107mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | A | JBL SA750 75th Anniversary Edition is the cheaper watt - about $23 per watt against $33. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A JBL SA750 75th Anniversary Edition B Yamaha A-S1200
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?
JBL SA750 75th Anniversary Edition has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. If you already own a DAC or a streamer, the built-in one is money you are paying twice for, and Yamaha A-S1200 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.