Mastering Compressor As a mastering compressor, IRON is inspired by the legendary vintage tube compressors à la Fairchild, Collins or Gates and has been developed in a way to give modern productions more energy and power with the advantages of the 120V technology. Input & Output Input and output levels are switchable in a control range of +/- 12dB. An increase of the input level leads to more intensive compression. When mastering full scale material, the reduction can be useful. The output is used to adjust the level ratios of input and output. Attack & Release The time parameters Attack and Release are switchable in six steps from Slow to Fast. The times vary depending on the rectifier circuit selected. Side Chain EQs With the side chain EQs, compression can be focused on frequency ranges. In addition to an inserted EQ, there are four internal EQ presets with a partly complex frequency response. Rectifier The tube stage is controlled by a rectifier circuit. There are six diode control characteristics generated by germanium, silicon and LED diodes or combinations thereof.