Both are Advance Paris, from different ranges - the engineering approach is shared and the differences are mostly in power, connectivity and price.
| Area | Better | Why |
|---|
| Power | B | Advance Paris A12 Classic has more power - 190W against 120W 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 increases modestly (183W and 280W). |
| Noise floor | A | Advance Paris A10 APEX is the quieter design on paper - 106dB against 100dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | evenly matched | Both have a DAC on board with much the same capability. |
| Room to grow | evenly matched | The same expansion options on both. |
| Shelf space | depends | Advance Paris A10 APEX takes up about 14% less shelf area (1762cm² against 2043cm²), and it is 65mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | Advance Paris A10 APEX costs less - $3,499 against $4,499 at list. |
A Advance Paris A10 APEX B Advance Paris A12 Classic
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?
Neither runs away with it - they trade advantages. Let the "depends" rows and the speakers you already own settle it.
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.