Devialet Expert Pro series is, essentially, a complete high-end audio system (just add speakers!) in a single chassis. Expert Pro 220 delivers 220 watts into a 6 ohm load. It integrates a 192K 32 bit DAC (total digital pathway for the DAC is 1.5 inches!). It integrates completely (full functionality) with Roon, and also runs Spotify and other services. It can handle a large series of inputs and outputs, both analog and digital. The new version (this one) handles every configuration imaginable (look at the web). It sounds great and looks great as well. Very fancy stand-alone remote can also operate directly from the Internet (as can all of the functions). Software amendments have increased functionality hugely, with more to come. These units can be purchased one at a time, or, if you have a bigger system, you might consider a pair of the units which then make up a Devialet 440. Even more punch and a very nice increase in sound quality as well. The future of audio has now arrived.