These are not the same size of amplifier: SVS Prime SoundBase has roughly 2.5x the power of Rega io. That is about 4dB, 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 | SVS Prime SoundBase has more power - 75W against 30W into 8 ohms. That is about 4dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Rega io the better fit for desk or near-field listening and a small room, and SVS Prime SoundBase 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. |
| Built-in DAC | B | SVS Prime SoundBase has a DAC on board; the other needs an external one, which is another box, another power lead and another purchase. |
| Streaming | B | Only SVS Prime SoundBase has AirPlay 2, Chromecast and DTS Play-Fi. |
| Analogue inputs | evenly matched | The same number of line-level inputs (2). |
| Phono stage | depends | Rega io has a built-in phono stage (MM) and SVS Prime SoundBase 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 | B | Only SVS Prime SoundBase offers preamp outputs and a subwoofer output - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Amplifier class | depends | Rega io is Class A/B and SVS Prime SoundBase 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. |
| Price | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | B | SVS Prime SoundBase is the cheaper watt - about $9 per watt against $24. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Rega io B SVS Prime SoundBase
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?
SVS Prime SoundBase 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 - SVS Prime SoundBase has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 30 watts is already more than most people ever use, and the extra 45 watts would be headroom you pay for and never hear - we rate SVS Prime SoundBase poorly for near-field use for exactly that reason. If you play records, Rega io 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.