Different price classes - Anthem STR Power Amplifier costs roughly 2.8x what Anthem MCA 225 Gen 2 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 | Anthem STR Power Amplifier has more power - 400W against 225W into 8 ohms. That is about 2.5dB, 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 | Anthem MCA 225 Gen 2 costs less - $2,300 against $6,500 at list. |
| Watts per dollar | B | Anthem MCA 225 Gen 2 is the cheaper watt - about $10 per watt against $16. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Anthem STR Power Amplifier B Anthem MCA 225 Gen 2
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. 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 - Anthem STR Power Amplifier has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 225 watts is already more than most people ever use, and the extra 175 watts would be headroom you pay for and never hear. Think about the whole system: the roughly $4,200 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.