A cascade reverse engineering approach is presented which uses an explicit model of the music production chain. The model considers both the mixing and the mastering stages and incorporates a parametric signal model. The approach is further pursued in an informed scenario. This means that the model parameters are attached in the form of auxiliary data to the mastered mix. They are resorted to afterwards in order to undo the mastering and the mixing. The validity of the approach is demonstrated on a stereo mixture.