The Lector Digitube S-192 is built into a chassis that's well styled without silly excess. A twopiece steel clamshell comprises the major portion of the enclosure, with steel front and rear panels and a sedately pretty faceplate of acrylic, with a tinted window for the digital display. The faceplate also includes a small pushbutton for toggling through input choices—the Digitube's only user control, apart from its side-mounted rocker power switch—and a row of five blue LEDs to indicate which input is currently in use. These correspond with five sets of rear-mounted input jacks: two electrical S/PDIF (RCA, BNC), one optical S/PDIF (TosLink), one AES/EBU (XLR), and, of course, one USB (Type B).
The well-finished chassis, supported by three nicely made alloy-and-rubber isolation feet, is filled with a total of seven circuit boards, on the largest of which are the power-supply and audio-output components—the latter including the pair of ECC81 dual-triode tubes that account for another portion of the Lector's name. Two boards adjacent to the rear panel handle the digital-input chores, the smaller built around a Tenor TE8802L USB streaming controller chip. Yet another board plays host to a 32-bit AK4397 DAC chip from Japan's Asahi Kasei Microdevices Corporation (AKM), supported by an AKM AK4113VF digital audio receiver chip. The parts quality is very good throughout, and I was impressed that current-to-voltage conversion appears to be handled by discrete resistors. In contrast with the makers of other recent source components, Lector has eschewed the use of a switching power supply, opting instead for a more traditional supply built around a toroidal mains transformer of reasonable size and apparently good quality. An unusually hefty, hand-terminated, detachable AC cord is supplied as standard.