These are not the same size of amplifier: SVS Prime SoundBase has roughly 3x the power of Arcam Solo Uno. That is about 4.8dB, 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 | SVS Prime SoundBase has more power - 75W against 25W into 8 ohms. That is about 4.8dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate SVS Prime SoundBase the better fit for a mid-size room, a large room and a very large room, and Arcam Solo Uno 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 | evenly matched | Both behave much the same into 4 ohms - output nearly doubles (150W and 50W). |
| Noise floor | B | Arcam Solo Uno is the quieter design on paper - 117dB against 90dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | B | Both decode on board, but only Arcam Solo Uno handles MQA. |
| Streaming | evenly matched | Only SVS Prime SoundBase has DTS Play-Fi; only Arcam Solo Uno has Roon. Neither list is longer in a way that matters - check the one service you actually pay for. |
| Analogue inputs | A | SVS Prime SoundBase takes more analogue sources - 2 against 1. |
| Use with a TV | depends | Only SVS Prime SoundBase has HDMI ARC/eARC, so the television can drive it directly and one remote controls the volume. If the system is for music only, this changes nothing. |
| Room to grow | evenly matched | The same expansion options on both. |
| Headphones | depends | Only SVS Prime SoundBase has a headphone output. Worth something if you listen late, nothing if you never do. |
| Shelf space | depends | Arcam Solo Uno takes up about 33% less shelf area (348cm² against 517cm²), and it is 21mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | A | SVS Prime SoundBase costs less - $699 against $769 at list. |
| Watts per dollar | A | SVS Prime SoundBase is the cheaper watt - about $9 per watt against $31. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A SVS Prime SoundBase B Arcam Solo Uno
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, 25 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 SVS Prime SoundBase poorly for near-field use for exactly that reason. If this sits under a television, SVS Prime SoundBase is the one to buy - HDMI ARC means the TV remote controls the volume and there is no second box in the way.
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.