This extremely rare, vintage unit, is virtually the most sought-after compressor in the audio world. Originally designed in 1957, these magnificent audio compressors were created with a “no expense spared” design philosophy, which would be economically impossible to recreate today. The 18 vacuum tube, 65 pound design is an outstanding credit to the engineers who created it. It operates as either a left channel/right channel compressor and it can be switched to operate in a lateral/vertical (MS mode). It has been copied and cloned as a “plug-in”, but never duplicated!