It's obvious that makers of desktop and personal audio systems have noticed the success of Sonos, 'cause they've started to emulate the company's products. But at least one higher-end audio company has noticed, too. AudioControl created the Rialto 400 as an upgrade amplifier for a Sonos system. Pair it with a Sonos Connect and you've got a high-powered system with a 120-watt-per-channel Class D amplifier, a subwoofer output, and numerous accessory inputs. It's even style to complement the Connect.