A valve amplifier against a solid-state one. They are not really rivals: they differ in character, in what they will drive and in what owning them involves, so start there rather than with the watts.
| Area | Better | Why |
|---|
| Power | B | NAD C 700 has more power - 80W against 10W into 8 ohms. That is about 9dB - a different class of amplifier rather than a bigger version of the same one, and far more than most rooms will ever ask for. |
| Room size | depends | We rate Layer Audio Design Gen-300B 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. |
| Built-in DAC | B | NAD C 700 has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Analogue inputs | evenly matched | The same number of line-level inputs (2). |
| Use with a TV | depends | Only NAD C 700 has HDMI eARC, so the television can drive it directly and one remote controls the volume. If the system is for music only, this changes nothing. |
| Headphones | depends | Only Layer Audio Design Gen-300B has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier type | depends | Layer Audio Design Gen-300B is Tube and NAD C 700 is Solid State. Valve designs are usually warmer and softer at the limits and need their tubes replaced eventually; solid state is the lower-maintenance choice. This is a taste and ownership decision, not a quality one. |
| Shelf space | depends | NAD C 700 takes up about 27% less shelf area (651cm² against 888cm²), and it is 31mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | B | NAD C 700 is the cheaper watt - about $19 per watt against $150. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Layer Audio Design Gen-300B 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 C 700 has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. 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, 10 watts is already more than most people ever use, and the extra 70 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 this sits under a television, NAD C 700 is the one to buy - HDMI ARC means the TV remote controls the volume and there is no second box in the way.
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.