These are not the same size of amplifier: NAD C 368 BluOS-2i has roughly 2.7x the power of Technics SU-GX70. That is about 4.3dB, 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 | B | NAD C 368 BluOS-2i has more power - 80W against 30W into 8 ohms. That is about 4.3dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Technics SU-GX70 the better fit for desk or near-field listening and a small room, and NAD C 368 BluOS-2i 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 | A | Technics SU-GX70 holds up better into a 4-ohm load: its output nearly doubles to 60W, where the other barely increases. That matters with demanding speakers far more than the 8-ohm figure does. |
| Built-in DAC | A | Both decode on board, but only Technics SU-GX70 handles DSD. |
| Streaming | evenly matched | Only Technics SU-GX70 has Chromecast; only NAD C 368 BluOS-2i has Roon and BluOS. Neither list is longer in a way that matters - check the one service you actually pay for. |
| Analogue inputs | evenly matched | The same number of line-level inputs (2). |
| Room to grow | evenly matched | The same expansion options on both. |
| Price | B | NAD C 368 BluOS-2i costs less - $1,749 against $1,999 at list. |
| Watts per dollar | B | NAD C 368 BluOS-2i is the cheaper watt - about $22 per watt against $67. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Technics SU-GX70 B NAD C 368 BluOS-2i
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?
Neither runs away with it - they trade advantages. Let the "depends" rows and the speakers you already own settle it. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Technics SU-GX70 is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. 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 BluOS-2i has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 30 watts is already more than most people ever use, and the extra 50 watts would be headroom you pay for and never hear - we rate NAD C 368 BluOS-2i poorly for near-field use for exactly that reason.
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.