The SPL Iron Red Mastering Compressor is a high-quality Vari-Mu compressor designed for mastering application.

The SPL Iron uses features no less than 6 valves for the rectifier stage which can be selected for different tonality, as well as another two on the input and output stages. Custom Lundahl transformers are also included on the input and output stage. The Iron uses SPL’s superb 120V technology which has been employed on the Neos ensuring extremely high headroom and low distortion for superb sonic performance.

A selection of four Sidechain EQ filters is included as well to modify the behaviour of the compressor which is also augmented by AirBass and TapeRollOff switches. Being a Vari-Mu design, the ratio is dependent on the gain reduction and therefore there are no ratio controls. Simply control the attack, release of threshold to control the level of compression while the rectifier and Side Chain EQ will change the colouration and behaviour of the compressor.

The Iron v2 now uses balanced side-chain inserts with send and return connections, replacing tho old jack connector, as well as new side-chain filter presets.