No single best amplifier here. What decides it is what you have to drive, what you need to plug in, and how much of the system you want in one box.
| Area | Better | Why |
|---|
| Power | A | Peachtree nova300 has more power - 300W against 180W into 8 ohms. That is about 2.2dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Grip on hard loads | A | Peachtree nova300 holds up better into a 4-ohm load: its output increases strongly to 450W, where the other barely increases. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | A | Peachtree nova300 is the quieter design on paper - 105dB against 95dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Both decode on board, but only Peachtree nova300 handles DSD. |
| Analogue inputs | evenly matched | The same number of line-level inputs (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. |
| Shelf space | depends | Peachtree nova300 takes up about 29% less shelf area (1289cm² against 1818cm²), and it is 56mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | Peachtree nova300 costs less - $1,499 against $1,999 at list. |
| Watts per dollar | A | Peachtree nova300 is the cheaper watt - about $5 per watt against $11. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Peachtree nova300 B NAD C 399
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 NAD C 399 if one of the "depends" rows above describes your system. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Peachtree nova300 is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. 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 - Peachtree nova300 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 180 watts is already more than most people ever use, and the extra 120 watts would be headroom you pay for and never hear - we rate Peachtree nova300 poorly for near-field use for exactly that reason.
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.