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 | evenly matched | Effectively the same output - 180W against 190W into 8 ohms is under 1dB, which is not an audible difference in loudness. |
| Grip on hard loads | B | Advance Paris A12 Classic holds up better into a 4-ohm load: its output increases modestly to 280W, where the other barely increases. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | B | Advance Paris A12 Classic is the quieter design on paper - 100dB against 95dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Both decode on board. NAD C 399 goes higher - 384kHz against 192kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Room to grow | B | Only Advance Paris A12 Classic offers a pre-out/main-in loop - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Amplifier type | depends | NAD C 399 is Solid State and Advance Paris A12 Classic is Hybrid. 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. |
| Price | A | NAD C 399 costs less - $2,899 against $4,499 at list. |
| Watts per dollar | A | NAD C 399 is the cheaper watt - about $16 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 NAD C 399 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?
Advance Paris A12 Classic is ahead, but on only 1 of the measured areas, and it costs about 55% more. That is a lot of money for a narrow margin - NAD C 399 is the sensible buy unless a specific feature above decides it for you. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Advance Paris A12 Classic is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. Think about the whole system: the roughly $1,600 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.