These are not the same size of amplifier: AudioControl Rialto 600 has roughly 2x the power of Audiolab 6000A. That is about 3dB, 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 | AudioControl Rialto 600 has more power - 100W against 50W into 8 ohms. That is about 3dB, so it plays usefully louder before it runs out and has more in hand on peaks. |
| Room size | depends | We rate Audiolab 6000A the better fit for desk or near-field listening and a small room, and AudioControl Rialto 600 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. |
| Grip on hard loads | B | AudioControl Rialto 600 holds up better into a 4-ohm load: its output nearly doubles to 200W, where the other increases strongly. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | B | AudioControl Rialto 600 is the quieter design on paper - 96dB against 76dB. Audible mainly with sensitive speakers in a quiet room. |
| Built-in DAC | evenly matched | Both have a DAC on board with much the same capability. |
| Analogue inputs | A | Audiolab 6000A takes more analogue sources - 4 against 1. |
| Phono stage | depends | Audiolab 6000A has a built-in phono stage (MM) and AudioControl Rialto 600 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 | A | Only Audiolab 6000A 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 6000A is Class A/B and AudioControl Rialto 600 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. |
| Shelf space | depends | AudioControl Rialto 600 takes up about 74% less shelf area (410cm² against 1605cm²), and it is 171mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | evenly matched | Priced within a few per cent of each other. |
| Watts per dollar | B | AudioControl Rialto 600 is the cheaper watt - about $9 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 6000A B AudioControl Rialto 600
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?
AudioControl Rialto 600 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 - AudioControl Rialto 600 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 - AudioControl Rialto 600 has the headroom, and headroom is what stops an amplifier hardening up on peaks. At desk distance or in a small room, 50 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 AudioControl Rialto 600 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.