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 | Schiit Tyr F has more power - 200W against 140W into 8 ohms. That is about 1.5dB, which is a small step in loudness but real headroom on peaks. |
| Room size | depends | We rate PS Audio Stellar S300 the better fit for desk or near-field listening, a small room and a mid-size room, and Schiit Tyr F for a very large room. Match the amplifier to the room you actually have, not the one you want. |
| Grip on hard loads | A | PS Audio Stellar S300 holds up better into a 4-ohm load: its output nearly doubles to 300W, where the other increases strongly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | B | Schiit Tyr F is the quieter design on paper - 120dB against 100dB. Audible mainly with sensitive speakers in a quiet room. |
| Analogue inputs | B | Schiit Tyr F takes more analogue sources - 2 against 1. |
| Amplifier class | depends | PS Audio Stellar S300 is Class D and Schiit Tyr 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 | B | Schiit Tyr F costs less - $1,699 against $1,999 at list. |
| Watts per dollar | B | Schiit Tyr F is the cheaper watt - about $8 per watt against $14. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A PS Audio Stellar S300 B Schiit Tyr 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?
Schiit Tyr F is the easier recommendation: it leads on most of the measured areas and costs less. Take PS Audio Stellar S300 if one of the "depends" rows above describes your system. If your speakers are a difficult load - 4 ohms nominal, big woofers, or a sensitivity in the low 80s - PS Audio Stellar S300 is the safer partner, because how an amplifier behaves when the impedance drops matters more than its 8-ohm rating.
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.