No single best amplifier here. What decides it is what you have to drive, what you need to plug in, and how much of the system you want in one box.
| Area | Better | Why |
|---|
| Power | B | Parasound NewClassic 2125 v.2 has more power - 150W against 100W into 8 ohms. That is about 1.8dB, which is a small step in loudness but real headroom on peaks. |
| 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 | Parasound NewClassic 2125 v.2 costs less - $1,250 against $1,499 at list. |
| Watts per dollar | B | Parasound NewClassic 2125 v.2 is the cheaper watt - about $8 per watt against $15. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Audiolab 9000P B Parasound NewClassic 2125 v.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?
Parasound NewClassic 2125 v.2 is the easier recommendation: it leads on most of the measured areas and costs less. Take Audiolab 9000P if one of the "depends" rows above describes your system.
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.