The Tube PAC from ART is a combination of the worldÆs most popular tube mic/line preamplifier and optical tube compressor. ART engineers took the Tube MP and Tube Compressor and combined them into a single convenient aircraft-quality, extruded aluminum chassis. This new table-top design allows for easy placement in the studio or on the stage with immediate access to all the controls, features, and metering. In addition to being a tremendous vocal and instrument preamplifier and compressor package, this may well be the ultimate in tube direct boxes!