The Klark Teknik DN504 Quad Compressor/Limiter has been designed to give the studio or PA engineer comprehensive and convenient automatic control over gain and level. Four channels of compression are available in one unit of nineteen inch rack space. As a Compressor, the DN504 can achieve almost undetectable dynamic range reduction by the use of sophisticated automatic attack and release circuitry. Compression can also be used as an effect in its own right with full manual control over Threshold, Ratio, Attack, Release and Gain. There is also a switchable 'Knee' control which provides the option of Hard or Soft compression styles. Four side chain inputs are provided. A stereo link function is available to allow channels to be linked in pairs to compress stereo signals while avoiding the possibility of image shift. PSU is switchable between 110V and 220V, currently set to work on 220V. Fuse has to be changed for 110V operation. EU power cord included.