Retailing for $2,195, the e.One S300iu utilizes the same casework as Bel Canto's e.One REF 1000M mono amplifiers, although the S300iu features a large input and volume display across its face, flanked by a single dial that controls volume, input selection and power on/off. The single dial interface is not quite intuitive at first; simply turning the dial will increase or decrease the volume, while pressing the dial in then turning it will shuttle through the S300iu's four inputs. To turn off the S300iu, simply press and hold the large dial down until the unit switches into standby mode, though I'm not sure you'll want to nor need to, for the S300iu is incredibly green, with an idle power draw of only 15 watts.
Speaking of watts, the S300iu is rated at 150 watts per channel into eight ohms and 300 watts per channel into four. It has a stated frequency response of 20Hz to 20kHz, with a total harmonic distortion rating of one percent. The S300iu has four unbalanced inputs simply named one through four, as well as a USB input for the S300iu's USB DAC. The S300iu also has Rec Out and a single Line Out, which can be used to integrate a subwoofer into your two-channel system or run a second power amplifier. The S300iu has a pair of robust binding posts that can accept all forms of speaker wire termination, from spade lugs to bare wire.
In terms of sound, the S300iu is one hundred percent Bel Canto, which is a good thing if you like digital switching amplifiers, but a bad thing if you don't. If you don't, I suggest you stop reading, for the S300iu isn't going to be for you. The S300iu has all the signature attributes of a digital switching amp, light and airy high-frequency playback mated to a slightly recessed yet very natural midrange, rounded out by very taut, controlled and agile bass that isn't earth-shattering but is very composed. The S300iu throws one hell of a convincing soundstage and the detail it's able to retrieve is rather astonishing. That being said, it can get a bit brittle-sounding at the extremes and lacks a bit of fullness and that analog "touch" you'll get from traditional amplifiers, including solid state designs.
Read The High Points, Low Points and Conclusion on Page 2