A valve amplifier against a solid-state one. They are not really rivals: they differ in character, in what they will drive and in what owning them involves, so start there rather than with the watts.
| Area | Better | Why |
|---|
| Power | B | Yamaha A-S1200 has more power - 90W against 40W into 8 ohms. That is about 3.5dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate PrimaLuna EVO 100 Power the better fit for desk or near-field listening and a small room, and Yamaha A-S1200 for a mid-size room, a large room and a very large room. Match the amplifier to the room you actually have, not the one you want. |
| Noise floor | B | Yamaha A-S1200 is the quieter design on paper - 110dB against 92dB. Audible mainly with sensitive speakers in a quiet room. |
| Analogue inputs | B | Yamaha A-S1200 takes more analogue sources - 6 against 1. |
| Phono stage | depends | Yamaha A-S1200 has a built-in phono stage (MM,MC) and PrimaLuna EVO 100 Power 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 Yamaha A-S1200 has a headphone output. Worth something if you listen late, nothing if you never do. |
| Amplifier type | depends | PrimaLuna EVO 100 Power is Tube and Yamaha A-S1200 is Solid State. Valve designs are usually warmer and softer at the limits and need their tubes replaced eventually; solid state is the lower-maintenance choice. This is a taste and ownership decision, not a quality one. |
| Shelf space | depends | PrimaLuna EVO 100 Power takes up about 47% less shelf area (1128cm² against 2123cm²), and it is 84mm 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 | Yamaha A-S1200 is the cheaper watt - about $33 per watt against $77. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A PrimaLuna EVO 100 Power B Yamaha A-S1200
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?
Yamaha A-S1200 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 - Yamaha A-S1200 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 40 watts is already more than most people ever use, and the extra 50 watts would be headroom you pay for and never hear - we rate Yamaha A-S1200 poorly for near-field use for exactly that reason. If you play records, Yamaha A-S1200 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.