These are not the same size of amplifier: TEAC AP-701B has roughly 2.4x the power of Technics SU-G700M2 Grand Class. That is about 3.9dB, 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 | TEAC AP-701B has more power - 170W against 70W into 8 ohms. That is about 3.9dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Analogue inputs | evenly matched | The same number of line-level inputs (2). |
| Price | B | Technics SU-G700M2 Grand Class costs less - $2,700 against $4,000 at list. |
| Watts per dollar | A | TEAC AP-701B is the cheaper watt - about $24 per watt against $39. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A TEAC AP-701B B Technics SU-G700M2 Grand Class
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: TEAC AP-701B measures better, Technics SU-G700M2 Grand Class costs about 33% 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 - TEAC AP-701B has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 70 watts is already more than most people ever use, and the extra 100 watts would be headroom you pay for and never hear. Think about the whole system: the roughly $1,300 saved by taking the cheaper one would buy better speakers or a subwoofer, which does more for the sound than the difference between two competent amplifiers.
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.