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 | A | Parasound NewClassic 200 Integrated has more power - 125W against 100W into 8 ohms. That is about 1dB, which is a small step in loudness but real headroom on peaks. |
| 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 barely increases. That matters with demanding speakers far more than the 8-ohm figure does. |
| Noise floor | A | Parasound NewClassic 200 Integrated is the quieter design on paper - 100dB against 96dB. 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 | Parasound NewClassic 200 Integrated takes more analogue sources - 4 against 1. |
| Phono stage | depends | Parasound NewClassic 200 Integrated has a built-in phono stage (MM,MC) 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 | evenly matched | The same expansion options on both. |
| Shelf space | depends | AudioControl Rialto 600 takes up about 78% less shelf area (410cm² against 1870cm²), and it is 238mm shallower, which is the measurement that decides whether a rack door shuts. |
| Price | B | AudioControl Rialto 600 costs less - $899 against $1,399 at list. |
A Parasound NewClassic 200 Integrated 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?
The usual trade-off: Parasound NewClassic 200 Integrated measures better, AudioControl Rialto 600 costs about 36% less. With most speakers in most rooms that gap is smaller in practice than it looks here. 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. If you play records, Parasound NewClassic 200 Integrated 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.