"Corona stands for the ideal fusion of high end sound & and innovative design concept. . . . [a] perfect match for almost any type of room interior," says MBL in its literature. The Corona C15 certainly looks very different from the high-end norm. There are none of the usual black heatsink fins, as the C15 uses a cool-running class-D output stage. Instead of the ubiquitous rectangular box, this modestly sized amplifier comes in an elegant white- or black-gloss–finished case, its center section finished in gold, or a chrome-like finish MBL calls Palinux. No fasteners are visible. Although its case is made of 4mm-thick aluminum (the vented rear panel is steel), the C15 is surprisingly heavy for a class-D design, at 48.5 lbs. This is due to the use of extensive internal magnetic shielding of mu-metal, an alloy of nickel, iron, copper, and chromium (or molybdenum).