These are not the same size of amplifier: Yamaha A-S501 has roughly 2.1x the power of NAD C316BEE V2. That is about 3.3dB, 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 | A | Yamaha A-S501 has more power - 85W against 40W into 8 ohms. That is about 3.3dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Yamaha A-S501 the better fit for a mid-size room, a large room and a very large room, and NAD C316BEE V2 for desk or near-field listening and a small room. Match the amplifier to the room you actually have, not the one you want. |
| Noise floor | A | Yamaha A-S501 is the quieter design on paper - 99dB against 95dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Yamaha A-S501 has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Analogue inputs | A | Yamaha A-S501 takes more analogue sources - 6 against 5. |
| Room to grow | A | Only Yamaha A-S501 offers preamp outputs - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Shelf space | depends | NAD C316BEE V2 takes up about 27% less shelf area (1253cm² against 1710cm²), and it is 105mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | NAD C316BEE V2 costs less - $499 against $550 at list. |
| Watts per dollar | A | Yamaha A-S501 is the cheaper watt - about $6 per watt against $12. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Yamaha A-S501 B NAD C316BEE V2
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-S501 leads across most of the measured areas for a fairly modest premium, so it is the easier pick if the budget stretches. NAD C316BEE V2 is the one to take if it does not. 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-S501 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 40 watts is already more than most people ever use, and the extra 45 watts would be headroom you pay for and never hear - we rate Yamaha A-S501 poorly for near-field use for exactly that reason. If you already own a DAC or a streamer, the built-in one is money you are paying twice for, and NAD C316BEE V2 becomes the more rational buy.
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.