Different price classes - Arcam SA20 costs roughly 1.7x what Audiolab 7000A does. Expect it to lead on paper; the question is whether you will hear the difference through the speakers you own.
| Area | Better | Why |
|---|
| Power | B | Arcam SA20 has more power - 90W against 70W into 8 ohms. That is about 1.1dB, which is a small step in loudness but real headroom on peaks. |
| Grip on hard loads | evenly matched | Both behave much the same into 4 ohms - output increases strongly (110W and 150W). |
| Noise floor | A | Audiolab 7000A is the quieter design on paper - 110dB against 106dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | A | Both decode on board, but only Audiolab 7000A handles DSD and MQA. |
| Analogue inputs | B | Arcam SA20 takes more analogue sources - 4 against 3. |
| Room to grow | A | Only Audiolab 7000A offers a pre-out/main-in loop - which decides whether you can add a subwoofer or a power amplifier later without replacing the box. |
| Amplifier class | depends | Audiolab 7000A is Class A/B and Arcam SA20 is Class G. Class A/B runs warm and is the long-established mainstream choice; Class G/H switches its supply rails to cut the heat a Class A/B design wastes. Modern examples of both measure well - judge by the rest of the page. |
| Price | A | Audiolab 7000A costs less - $999 against $1,650 at list. |
| Watts per dollar | A | Audiolab 7000A is the cheaper watt - about $14 per watt against $18. A blunt measure, and it says nothing about how either sounds, but it is the honest one for raw output. |
A Audiolab 7000A B Arcam SA20
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?
Audiolab 7000A is the easier recommendation: it leads on most of the measured areas and costs less. Take Arcam SA20 if one of the "depends" rows above describes your system. Think about the whole system: the roughly $651 saved by taking the cheaper one would buy better speakers or a subwoofer, which does more for the sound than the difference between two competent amplifiers.
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.