These are not the same size of amplifier: Rotel RA-1572 MKII has roughly 4.8x the power of Rotel DX-5. That is about 6.8dB, so it is a question of room size and how hard your speakers are to drive, not of one being the better amplifier.
| Area | Better | Why |
|---|
| Power | B | Rotel RA-1572 MKII has more power - 120W against 25W into 8 ohms. That is about 6.8dB - a different class of amplifier rather than a bigger version of the same one, and far more than most rooms will ever ask for. |
| Grip on hard loads | B | Rotel RA-1572 MKII holds up better into a 4-ohm load: its output increases strongly to 200W, where the other increases modestly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | evenly matched | Much the same signal-to-noise ratio (100dB vs 100dB). |
| Built-in DAC | B | Both decode on board, but only Rotel RA-1572 MKII handles MQA. |
| Streaming | evenly matched | The same streaming platforms and services on both. |
| Phono stage | depends | Rotel RA-1572 MKII has a built-in phono stage (MM) and Rotel DX-5 does not. Decisive if you own a turntable, completely irrelevant if you do not - and an outboard phono stage is easy to add later either way. |
| Room to grow | B | Only Rotel RA-1572 MKII offers preamp outputs - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Shelf space | depends | Rotel DX-5 takes up about 64% less shelf area (610cm² against 1675cm²), and it is 103mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | Rotel DX-5 costs less - $1,699 against $2,100 at list. |
| Watts per dollar | B | Rotel RA-1572 MKII is the cheaper watt - about $18 per watt against $68. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Rotel DX-5 B Rotel RA-1572 MKII
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?
Rotel RA-1572 MKII leads across most of the measured areas for a fairly modest premium, so it is the easier pick if the budget stretches. Rotel DX-5 is the one to take if it does not. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Rotel RA-1572 MKII is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. 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 - Rotel RA-1572 MKII has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 25 watts is already more than most people ever use, and the extra 95 watts would be headroom you pay for and never hear - we rate Rotel RA-1572 MKII poorly for near-field use for exactly that reason.
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.