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 200W into 8 ohms. That is about 1.8dB, which is a small step in loudness but real headroom on peaks. |
| Grip on hard loads | B | Rotel Diamond RA-6000 holds up better into a 4-ohm load: its output increases strongly to 350W, where the other increases strongly. That matters with demanding speakers far more than the 8-ohm figure does. |
| 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 $4,500 at list. |
| Watts per dollar | A | Peachtree nova300 is the cheaper watt - about $5 per watt against $23. 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 has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Rotel Diamond RA-6000 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 $3,001 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.