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 | evenly matched | Effectively the same output - 120W against 130W 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 | B | JBL SA750 75th Anniversary Edition is the quieter design on paper - 112dB against 100dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Both decode on board. Rotel RA-1572 MKII goes higher - 384kHz against 192kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Streaming | B | Only JBL SA750 75th Anniversary Edition has AirPlay 2 and Chromecast. |
| Analogue inputs | evenly matched | The same number of line-level inputs (4). |
| Room to grow | evenly matched | The same expansion options on both. |
| Amplifier class | depends | Rotel RA-1572 MKII is Class A/B and JBL SA750 75th Anniversary Edition is Class G. Class A/B runs warm and is the long-established mainstream choice; Class G/H switches its supply rails to cut the heat a Class A/B design wastes. Modern examples of both measure well - judge by the rest of the page. |
| Price | A | Rotel RA-1572 MKII costs less - $2,100 against $3,000 at list. |
| Watts per dollar | A | Rotel RA-1572 MKII is the cheaper watt - about $18 per watt against $23. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Rotel RA-1572 MKII B JBL SA750 75th Anniversary Edition
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. Think about the whole system: the roughly $900 saved by taking the cheaper one would buy better speakers or a subwoofer, which does more for the sound than the difference between two competent amplifiers.
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.