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 | A | JBL MA7100HP has more power - 125W against 95W into 8 ohms. That is about 1.2dB, which is a small step in loudness but real headroom on peaks. |
| Analogue inputs | B | Denon AVR-X2900H takes more analogue sources - 4 against 2. |
| Room to grow | evenly matched | The same expansion options on both. |
| Built-in sources | depends | Denon AVR-X2900H has a radio tuner built in. That is one less box if you still play discs or listen to radio, and dead weight if you do not. |
| Amplifier class | depends | JBL MA7100HP is D and Denon AVR-X2900H is AB. Class D runs cool and draws almost nothing at idle; Class A/B runs warm and is the long-established mainstream choice. Modern examples of both measure well - judge by the rest of the page. |
| Shelf space | depends | Denon AVR-X2900H takes up about 15% less shelf area (1559cm² against 1837cm²), and it is 67mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | A | JBL MA7100HP is the cheaper watt - about $11 per watt against $14. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A JBL MA7100HP B Denon AVR-X2900H
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?
JBL MA7100HP has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is.
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.