These are not the same size of amplifier: Buchardt I150 has roughly 3x the power of MOON 250i v2. That is about 4.8dB, 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 | B | Buchardt I150 has more power - 150W against 50W into 8 ohms. That is about 4.8dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate MOON 250i v2 the better fit for desk or near-field listening, a small room and a mid-size room, and Buchardt I150 for a large room and a very large room. Match the amplifier to the room you actually have, not the one you want. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output nearly doubles (100W and 300W). |
| Noise floor | B | Buchardt I150 is the quieter design on paper - 121dB against 101dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | B | Buchardt I150 has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Analogue inputs | A | MOON 250i v2 takes more analogue sources - 6 against 1. |
| Phono stage | depends | MOON 250i v2 has a built-in phono stage (MM) and Buchardt I150 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. |
| Headphones | depends | Only MOON 250i v2 has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier class | depends | MOON 250i v2 is Class A/B and Buchardt I150 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. |
| Shelf space | depends | Buchardt I150 takes up about 27% less shelf area (1147cm² against 1570cm²), and it is 56mm 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 | B | Buchardt I150 is the cheaper watt - about $17 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 MOON 250i v2 B Buchardt I150
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?
Buchardt I150 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 - Buchardt I150 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 50 watts is already more than most people ever use, and the extra 100 watts would be headroom you pay for and never hear - we rate Buchardt I150 poorly for near-field use for exactly that reason. If you play records, MOON 250i v2 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.