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 368 has more power - 80W against 35W into 8 ohms. That is about 3.6dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Cayin Jazz 70 the better fit for desk or near-field listening and a small room, and NAD C 368 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. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output barely increases (35W and 80W). |
| Noise floor | evenly matched | Much the same signal-to-noise ratio (100dB vs 98dB). |
| Built-in DAC | evenly matched | Both have a DAC on board with much the same capability. |
| Analogue inputs | A | Cayin Jazz 70 takes more analogue sources - 3 against 2. |
| Phono stage | depends | NAD C 368 has a built-in phono stage (MM) and Cayin Jazz 70 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. |
| Amplifier type | depends | Cayin Jazz 70 is Tube and NAD C 368 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 | Cayin Jazz 70 takes up about 45% less shelf area (1014cm² against 1840cm²), and it is 85mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | Cayin Jazz 70 costs less - $1,399 against $1,499 at list. |
| Watts per dollar | B | NAD C 368 is the cheaper watt - about $19 per watt against $40. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Cayin Jazz 70 B NAD C 368
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?
The usual trade-off: NAD C 368 measures better, Cayin Jazz 70 costs about 7% less. With most speakers in most rooms that gap is smaller in practice than it looks here. 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 368 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 35 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 NAD C 368 poorly for near-field use for exactly that reason. If you play records, NAD C 368 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.