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 | B | Rotel Diamond RA-6000 has more power - 235W against 180W into 8 ohms. That is about 1.2dB, which is a small step in loudness but real headroom on peaks. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output increases strongly (272W and 350W). |
| Noise floor | evenly matched | Much the same signal-to-noise ratio (104dB vs 103dB). |
| Built-in DAC | B | Both decode on board. Rotel Diamond RA-6000 goes higher - 384kHz against 192kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Streaming | evenly matched | Only Rotel Diamond RA-6000 has Roon. Neither list is longer in a way that matters - check the one service you actually pay for. |
| Use with a TV | depends | Only Advance Paris A12 APEX has HDMI, so the television can drive it directly and one remote controls the volume. If the system is for music only, this changes nothing. |
| Room to grow | A | Only Advance Paris A12 APEX 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 | Advance Paris A12 APEX is Hybrid and Rotel Diamond RA-6000 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. |
| Price | B | Rotel Diamond RA-6000 costs less - $4,499 against $4,999 at list. |
| Watts per dollar | B | Rotel Diamond RA-6000 is the cheaper watt - about $19 per watt against $28. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Advance Paris A12 APEX B Rotel Diamond RA-6000
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?
Rotel Diamond RA-6000 is the easier recommendation: it leads on most of the measured areas and costs less. Take Advance Paris A12 APEX if one of the "depends" rows above describes your system. If this sits under a television, Advance Paris A12 APEX is the one to buy - HDMI ARC means the TV remote controls the volume and there is no second box in the way.
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.