These are not the same size of amplifier: Yamaha A-S301 has roughly 2x the power of NAD D 3020 V2. That is about 3dB, so it is a question of room size and how hard your speakers are to drive, not of one being the better amplifier.
| Area | Better | Why |
|---|
| Power | B | Yamaha A-S301 has more power - 60W against 30W into 8 ohms. That is about 3dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate NAD D 3020 V2 the better fit for desk or near-field listening, and Yamaha A-S301 for a very large room. Match the amplifier to the room you actually have, not the one you want. |
| Noise floor | evenly matched | Much the same signal-to-noise ratio (98dB vs 99dB). |
| Built-in DAC | B | Both decode on board. Yamaha A-S301 goes higher - 192kHz against 96kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Analogue inputs | B | Yamaha A-S301 takes more analogue sources - 6 against 1. |
| Room to grow | evenly matched | The same expansion options on both. |
| Amplifier class | depends | NAD D 3020 V2 is Class D and Yamaha A-S301 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 | NAD D 3020 V2 takes up about 91% less shelf area (146cm² against 1701cm²), and it is 143mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | Yamaha A-S301 costs less - $350 against $499 at list. |
| Watts per dollar | B | Yamaha A-S301 is the cheaper watt - about $6 per watt against $17. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A NAD D 3020 V2 B Yamaha A-S301
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?
Yamaha A-S301 is the easier recommendation: it leads on most of the measured areas and costs less. Take NAD D 3020 V2 if one of the "depends" rows above describes your system. 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 - Yamaha A-S301 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 30 watts is already more than most people ever use, and the extra 30 watts would be headroom you pay for and never hear. Think about the whole system: the roughly $149 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.