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 | B | Cambridge CXA81 II has more power - 80W against 50W into 8 ohms. That is about 2dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Rega Brio Mk 7 the better fit for desk or near-field listening and a small room, and Cambridge CXA81 II for a mid-size room, a large room and a very large 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 modestly (72W and 120W). |
| Built-in DAC | B | Both decode on board. Cambridge CXA81 II goes higher - 384kHz against 192kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Analogue inputs | B | Cambridge CXA81 II takes more analogue sources - 5 against 4. |
| Phono stage | depends | Rega Brio Mk 7 has a built-in phono stage (MM) and Cambridge CXA81 II 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. |
| Shelf space | depends | Rega Brio Mk 7 takes up about 51% less shelf area (788cm² against 1595cm²). |
| Price | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | B | Cambridge CXA81 II is the cheaper watt - about $15 per watt against $24. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Rega Brio Mk 7 B Cambridge CXA81 II
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?
Cambridge CXA81 II has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. 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 - Cambridge CXA81 II has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 50 watts is already more than most people ever use, and the extra 30 watts would be headroom you pay for and never hear - we rate Cambridge CXA81 II poorly for near-field use for exactly that reason. If you play records, Rega Brio Mk 7 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.