A valve amplifier against a solid-state one. They are not really rivals: they differ in character, in what they will drive and in what owning them involves, so start there rather than with the watts.
| Area | Better | Why |
|---|
| Power | A | Advance Paris A10 APEX has more power - 120W against 75W 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 110W). |
| Noise floor | A | Advance Paris A10 APEX is the quieter design on paper - 106dB against 90dB. 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. |
| Amplifier type | depends | Advance Paris A10 APEX is Hybrid and Advance Paris X-i75 is Solid State. Valve designs are usually warmer and softer at the limits and need their tubes replaced eventually; solid state is the lower-maintenance choice. This is a taste and ownership decision, not a quality one. |
| Shelf space | depends | Advance Paris X-i75 takes up about 15% less shelf area (1494cm² against 1762cm²), and it is 62mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | Advance Paris X-i75 costs less - $1,299 against $3,499 at list. |
| Watts per dollar | B | Advance Paris X-i75 is the cheaper watt - about $17 per watt against $29. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Advance Paris A10 APEX B Advance Paris X-i75
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?
Advance Paris A10 APEX is ahead, but on only 1 of the measured areas, and it costs about 2.7x the price. That is a lot of money for a narrow margin - Advance Paris X-i75 is the sensible buy unless a specific feature above decides it for you. 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 - Advance Paris A10 APEX 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 45 watts would be headroom you pay for and never hear. Think about the whole system: the roughly $2,200 saved by taking the cheaper one would buy better speakers or a subwoofer, which does more for the sound than the difference between two competent amplifiers.
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.