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 | A | Peachtree nova300 has more power - 300W against 235W into 8 ohms. That is about 1.1dB, 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 modestly (450W and 350W). |
| Noise floor | evenly matched | Much the same signal-to-noise ratio (105dB vs 103dB). |
| Built-in DAC | evenly matched | Both have a DAC on board with much the same capability. |
| 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. |
| Analogue inputs | B | Rotel Diamond RA-6000 takes more analogue sources - 4 against 2. |
| Room to grow | A | Only Peachtree nova300 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 class | depends | Peachtree nova300 is Class D and Rotel Diamond RA-6000 is Class A/B. Class D runs cool and draws almost nothing at idle; Class A/B runs warm and is the long-established mainstream choice. Modern examples of both measure well - judge by the rest of the page. |
| Shelf space | depends | Peachtree nova300 takes up about 35% less shelf area (1289cm² against 1979cm²), and it is 94mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | Peachtree nova300 costs less - $1,499 against $4,499 at list. |
| Watts per dollar | A | Peachtree nova300 is the cheaper watt - about $5 per watt against $19. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Peachtree nova300 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?
Peachtree nova300 is the easier recommendation: it leads on most of the measured areas and costs less. Take Rotel Diamond RA-6000 if one of the "depends" rows above describes your system. Think about the whole system: the roughly $3,000 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.