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 | B | NAD C 700 has more power - 80W against 60W into 8 ohms. That is about 1.2dB, which is a small step in loudness but real headroom on peaks. |
| Room size | depends | We rate NAD D 3045 the better fit for desk or near-field listening and a small room, and NAD C 700 for a mid-size room, a large room and a very large room. Match the amplifier to the room you actually have, not the one you want. |
| Noise floor | A | NAD D 3045 is the quieter design on paper - 98dB against 84dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Both decode on board. NAD D 3045 goes higher - 384kHz against 192kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Streaming | B | Only NAD C 700 has AirPlay 2, Roon and BluOS. |
| Analogue inputs | evenly matched | The same number of line-level inputs (2). |
| Phono stage | depends | NAD D 3045 has a built-in phono stage (MM) and NAD C 700 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. |
| Room to grow | evenly matched | The same expansion options on both. |
| Headphones | depends | Only NAD D 3045 has a headphone output. Worth something if you listen late, nothing if you never do. |
| Shelf space | depends | NAD D 3045 takes up about 68% less shelf area (208cm² against 651cm²). |
| Price | A | NAD D 3045 costs less - $899 against $1,599 at list. |
| Watts per dollar | A | NAD D 3045 is the cheaper watt - about $15 per watt against $20. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A NAD D 3045 B NAD C 700
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?
NAD D 3045 has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. If you play records, NAD D 3045 saves you buying a phono stage; if you do not, ignore that row entirely. Think about the whole system: the roughly $700 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.