These are not the same size of amplifier: Hegel H20 has roughly 2.7x the power of Hegel H150. That is about 4.3dB, so it is a question of room size and how hard your speakers are to drive, not of one being the better amplifier.
| Area | Better | Why |
|---|
| Power | A | Hegel H20 has more power - 200W against 75W into 8 ohms. That is about 4.3dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Hegel H20 the better fit for a large room and a very large room, and Hegel H150 for desk or near-field listening, a small room and a mid-size room. Match the amplifier to the room you actually have, not the one you want. |
| Bass control | B | Hegel H150 has the higher damping factor (2000 vs 1000), which usually means a tighter grip on a woofer. Above about 100 the returns flatten out, so read this as a tendency rather than a ranking. |
| Noise floor | evenly matched | Much the same signal-to-noise ratio (100dB vs 100dB). |
| Built-in DAC | B | Hegel H150 has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Analogue inputs | B | Hegel H150 takes more analogue sources - 3 against 2. |
| Phono stage | depends | Hegel H150 has a built-in phono stage (MM) and Hegel H20 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. |
| Price | B | Hegel H150 costs less - $3,600 against $7,200 at list. |
| Watts per dollar | A | Hegel H20 is the cheaper watt - about $36 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 H20 B Hegel H150
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?
Hegel H150 has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. 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 - Hegel H20 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 75 watts is already more than most people ever use, and the extra 125 watts would be headroom you pay for and never hear - we rate Hegel H20 poorly for near-field use for exactly that reason. If you play records, Hegel H150 saves you buying a phono stage; if you do not, ignore that row entirely.
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.