The Opal is a two-piece line-stage preamp with a 39-pound control unit linked via an umbilical DC-shielded cord with 30-amp Neutrik connectors to an 18-pound power supply. Both pieces, aside from color, are conventional looking enough. But a closer look (and touch) reveals decidedly unconventional construction- a control chassis of thick machined aluminum plates bolted to square posts provides solidity as well as external radio-frequency shielding.