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 |
|---|
| Built-in DAC | evenly matched | Both have a DAC on board with much the same capability. |
| Streaming | A | Only Bose Music Amplifier has AirPlay 2 and Chromecast. |
| Shelf space | depends | Bose Music Amplifier takes up about 63% less shelf area (500cm² against 1349cm²), and it is 87mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | Bose Music Amplifier costs less - $579 against $699 at list. |
A Bose Music Amplifier B NAD C 328
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?
Bose Music Amplifier has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is.
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.