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 | Rotel S14 has more power - 80W against 50W into 8 ohms. That is about 2dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Audiolab Omnia the better fit for desk or near-field listening and a small room, and Rotel S14 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. |
| Grip on hard loads | B | Rotel S14 holds up better into a 4-ohm load: its output nearly doubles to 150W, where the other increases strongly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | B | Rotel S14 is the quieter design on paper - 100dB against 76dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Both decode on board. Audiolab Omnia goes higher - 768kHz against 384kHz. Very few recordings exist above 192kHz, so treat this as headroom, not as sound quality. |
| Streaming | evenly matched | Only Audiolab Omnia has DTS Play-Fi; only Rotel S14 has AirPlay 2 and Chromecast. Neither list is longer in a way that matters - check the one service you actually pay for. |
| Analogue inputs | A | Audiolab Omnia takes more analogue sources - 4 against 1. |
| Phono stage | depends | Audiolab Omnia has a built-in phono stage (MM) and Rotel S14 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. |
| Room to grow | A | Only Audiolab Omnia offers a pre-out/main-in loop - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Built-in sources | depends | Audiolab Omnia has a CD player built in. That is one less box if you still play discs or listen to radio, and dead weight if you do not. |
| Price | A | Audiolab Omnia costs less - $2,300 against $2,499 at list. |
| Watts per dollar | B | Rotel S14 is the cheaper watt - about $31 per watt against $46. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Audiolab Omnia B Rotel S14
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?
The usual trade-off: Rotel S14 measures better, Audiolab Omnia costs about 8% less. With most speakers in most rooms that gap is smaller in practice than it looks here. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Rotel S14 is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating. 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 - Rotel S14 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 30 watts would be headroom you pay for and never hear - we rate Rotel S14 poorly for near-field use for exactly that reason.
What a spec sheet cannot show: how either sounds with your speakers, how the interface feels 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.