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 - 75W against 70W 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 nearly doubles (150W and 140W). |
| Built-in DAC | A | Both decode on board, but only Cambridge Audio Evo 75 handles DSD. |
| Streaming | A | Only Cambridge Audio Evo 75 has AirPlay 2, Chromecast and Roon. |
| Analogue inputs | B | Technics SU-G700M2 Grand Class takes more analogue sources - 2 against 1. |
| Phono stage | depends | Technics SU-G700M2 Grand Class has a built-in phono stage (MM,MC) and Cambridge Audio Evo 75 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 | evenly matched | The same expansion options on both. |
| Shelf space | depends | Cambridge Audio Evo 75 takes up about 42% less shelf area (1190cm² against 2069cm²), and it is 108mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | Cambridge Audio Evo 75 costs less - $2,499 against $2,700 at list. |
A Cambridge Audio Evo 75 B Technics SU-G700M2 Grand Class
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 Audio Evo 75 has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. If you play records, Technics SU-G700M2 Grand Class 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.