The AVA Vision DAC is an outstanding implementation of the Wolfson 8742 digital chip set. The design has a 2000 volt per microsecond slew rate and less than 0.0003 percent harmonic distortion. There is no feedback in this circuit at all. There is no voltage amplification so there is no need for tubes, transistors, or op-amps, and none are used. These circuits are based upon a current amplifier device with a quarter ampere current drive and a standard (resistively set) 560 ohm output impedance. It will drive any rational load, long cables, and passive controls with ease.
The Vision EC DAC provides multiple digital inputs. Two Toslink optical inputs and two RCA Jack coax inputs that are switchable from the front panel. This allows connection to any available sources, including the optical digital output of your computer at the bit rates mentioned above. Note that a USB input is not provided because high bit rate USB computer output requires software driver programs, and we simply do not want to get into the software support business. The optical inputs provide the necessary computer interface. Of course, diehards can add a separate USB to optical or USB to coax converter box if they desire (available inexpensively from many sources).
This DAC is from 2011 production and is in great shape. It does have a captive power cord.
One year parts and labor warranty.