Different price classes - Sony STR-AN1000 costs roughly 1.8x what Denon AVR-S670H does. Expect it to lead on paper; the question is whether you will hear the difference through the speakers you own.
| Area | Better | Why |
|---|
| Power | A | Sony STR-AN1000 has more power - 100W against 75W into 8 ohms. That is about 1.2dB, which is a small step in loudness but real headroom on peaks. |
| Speaker load rating | B | Denon AVR-S670H is rated down to 4 ohms against 6, so it is the safer partner for a low-impedance speaker. |
| Analogue inputs | A | Sony STR-AN1000 takes more analogue sources - 3 against 2. |
| Phono stage | depends | Denon AVR-S670H has a built-in phono stage and Sony STR-AN1000 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. |
| Room to grow | evenly matched | The same expansion options on both. |
| Price | B | Denon AVR-S670H costs less - $649 against $1,148 at list. |
| Watts per dollar | B | Denon AVR-S670H is the cheaper watt - about $9 per watt against $11. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Sony STR-AN1000 B Denon AVR-S670H
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 you play records, Denon AVR-S670H saves you buying a phono stage; if you do not, ignore that row entirely. Think about the whole system: the roughly $499 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.