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 | B | HiFi Rose RA180 has more power - 400W against 250W into 8 ohms. That is about 2dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output barely increases (250W and 400W). |
| Noise floor | evenly matched | Much the same signal-to-noise ratio (109dB vs 107dB). |
| Built-in DAC | A | HiFi Rose RS520 has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Streaming | evenly matched | Only HiFi Rose RS520 has Roon. Neither list is longer in a way that matters - check the one service you actually pay for. |
| Analogue inputs | B | HiFi Rose RA180 takes more analogue sources - 4 against 1. |
| Phono stage | depends | HiFi Rose RA180 has a built-in phono stage (MM,MC) and HiFi Rose RS520 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 HiFi Rose RA180 offers A/B speaker terminals - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Shelf space | depends | HiFi Rose RS520 takes up about 41% less shelf area (1135cm² against 1909cm²), and it is 115mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | HiFi Rose RS520 costs less - $3,695 against $6,995 at list. |
A HiFi Rose RS520 B HiFi Rose RA180
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: HiFi Rose RA180 measures better, HiFi Rose RS520 costs about 47% less. With most speakers in most rooms that gap is smaller in practice than it looks here. 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 - HiFi Rose RA180 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 250 watts is already more than most people ever use, and the extra 150 watts would be headroom you pay for and never hear - we rate HiFi Rose RA180 poorly for near-field use for exactly that reason. If you play records, HiFi Rose RA180 saves you buying a phono stage; if you do not, ignore that row entirely.
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.