These are not the same size of amplifier: FiiO AIR AMP has roughly 9x the power of Schiit Gjallarhorn F. That is about 9.5dB, 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 | FiiO AIR AMP has more power - 90W against 10W into 8 ohms. That is about 9.5dB - a different class of amplifier rather than a bigger version of the same one, and far more than most rooms will ever ask for. |
| Room size | depends | We rate FiiO AIR AMP the better fit for a mid-size room, a large room and a very large room, and Schiit Gjallarhorn F for desk or near-field listening and a small room. Match the amplifier to the room you actually have, not the one you want. |
| Grip on hard loads | B | Schiit Gjallarhorn F holds up better into a 4-ohm load: its output increases strongly to 15W, where the other increases modestly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Built-in DAC | A | FiiO AIR AMP has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Analogue inputs | B | Schiit Gjallarhorn F takes more analogue sources - 2 against 1. |
| Amplifier class | depends | FiiO AIR AMP is Class D and Schiit Gjallarhorn F is Class A/B. Class D runs cool and draws almost nothing at idle; Class A/B runs warm and is the long-established mainstream choice. 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 | A | FiiO AIR AMP is the cheaper watt - about $3 per watt against $30. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A FiiO AIR AMP B Schiit Gjallarhorn F
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?
FiiO AIR AMP has the edge on paper, though not by much. The rows marked "depends" are more likely to decide this than the score is. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - Schiit Gjallarhorn F 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 - FiiO AIR AMP has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 10 watts is already more than most people ever use, and the extra 80 watts would be headroom you pay for and never hear - we rate FiiO AIR AMP poorly for near-field use for exactly that reason.
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.