These are not the same size of amplifier: WiiM Amp Pro 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 | WiiM Amp Pro 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 WiiM Amp Pro for a very large room. Match the amplifier to the room you actually have, not the one you want. |
| Noise floor | B | WiiM Amp Pro is the quieter design on paper - 105dB against 98dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | B | Both decode on board. WiiM Amp Pro goes higher - 192kHz against 96kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Streaming | B | Only WiiM Amp Pro has Chromecast and Roon. |
| Phono stage | depends | NAD D 3020 V2 has a built-in phono stage (MM) and WiiM Amp Pro does not. Decisive if you own a turntable, completely irrelevant if you do not - and an outboard phono stage is easy to add later either way. |
| Use with a TV | depends | Only WiiM Amp Pro has HDMI ARC, 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 | evenly matched | The same expansion options on both. |
| Shelf space | depends | NAD D 3020 V2 takes up about 65% less shelf area (146cm² against 420cm²), and it is 28mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | WiiM Amp Pro costs less - $379 against $499 at list. |
| Watts per dollar | B | WiiM Amp Pro 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 WiiM Amp Pro
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?
WiiM Amp Pro 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 - WiiM Amp Pro 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. If you play records, NAD D 3020 V2 saves you buying a phono stage; if you do not, ignore that row entirely.
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.