These are not the same size of amplifier: Parasound Halo A23+ has roughly 2.1x the power of Cambridge Audio Evo 75. That is about 3.3dB, 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 | A | Parasound Halo A23+ has more power - 160W against 75W into 8 ohms. That is about 3.3dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Parasound Halo A23+ the better fit for a large room and a very large room, and Cambridge Audio Evo 75 for desk or near-field listening, a small room and a mid-size room. Match the amplifier to the room you actually have, not the one you want. |
| Grip on hard loads | B | Cambridge Audio Evo 75 holds up better into a 4-ohm load: its output nearly doubles to 150W, where the other increases strongly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Built-in DAC | B | Cambridge Audio Evo 75 has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Analogue inputs | A | Parasound Halo A23+ takes more analogue sources - 2 against 1. |
| Use with a TV | depends | Only Cambridge Audio Evo 75 has HDMI ARC, so the television can drive it directly and one remote controls the volume. If the system is for music only, this changes nothing. |
| Headphones | depends | Only Cambridge Audio Evo 75 has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier class | depends | Parasound Halo A23+ is Class A/AB and Cambridge Audio Evo 75 is Class D. Class D runs cool and draws almost nothing at idle. Modern examples of both measure well - judge by the rest of the page. |
| Shelf space | depends | Cambridge Audio Evo 75 takes up about 30% less shelf area (1190cm² against 1695cm²). |
| Price | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | A | Parasound Halo A23+ is the cheaper watt - about $16 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 Parasound Halo A23+ B Cambridge Audio Evo 75
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?
Parasound Halo A23+ has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Cambridge Audio Evo 75 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 - Parasound Halo A23+ has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 75 watts is already more than most people ever use, and the extra 85 watts would be headroom you pay for and never hear - we rate Parasound Halo A23+ 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.