Siblings in NAD's Classic range, so they share a design and a house sound. It comes down to power, features and price.
| Area | Better | Why |
|---|
| Power | A | NAD C 700 has more power - 80W against 50W into 8 ohms. That is about 2dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate NAD C 700 the better fit for a mid-size room, a large room and a very large room, and NAD C 338 for desk or near-field listening and a small room. Match the amplifier to the room you actually have, not the one you want. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output barely increases (80W and 50W). |
| Noise floor | B | NAD C 338 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, but only NAD C 700 handles MQA. |
| Streaming | A | Only NAD C 700 has AirPlay 2, Roon and BluOS; only NAD C 338 has Chromecast. |
| Analogue inputs | evenly matched | The same number of line-level inputs (2). |
| Phono stage | depends | NAD C 338 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 C 338 has a headphone output. Worth something if you listen late, nothing if you never do. |
| Shelf space | depends | NAD C 700 takes up about 52% less shelf area (651cm² against 1349cm²). |
| Price | B | NAD C 338 costs less - $799 against $1,599 at list. |
| Watts per dollar | B | NAD C 338 is the cheaper watt - about $16 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 C 700 B NAD C 338
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 C 700 is ahead, but on only 1 of the measured areas, and it costs about 100% more. That is a lot of money for a narrow margin - NAD C 338 is the sensible buy unless a specific feature above decides it for you. 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 - NAD C 700 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 50 watts is already more than most people ever use, and the extra 30 watts would be headroom you pay for and never hear - we rate NAD C 700 poorly for near-field use for exactly that reason. If you play records, NAD C 338 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.