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 | PS Audio Stellar Strata MK2 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. |
| Built-in DAC | evenly matched | Both have a DAC on board with much the same capability. |
| Analogue inputs | A | Hegel H150 takes more analogue sources - 3 against 1. |
| Headphones | depends | Only PS Audio Stellar Strata MK2 has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier class | depends | Hegel H150 is Class A/B and PS Audio Stellar Strata MK2 is Class D. Class A/B runs warm and is the long-established mainstream choice; Class D runs cool and draws almost nothing at idle. Modern examples of both measure well - judge by the rest of the page. |
| Price | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | B | PS Audio Stellar Strata MK2 is the cheaper watt - about $35 per watt against $48. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Hegel H150 B PS Audio Stellar Strata MK2
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?
PS Audio Stellar Strata MK2 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.