The combination of a high-quality compressor with a sophisticated de-esser provides the engineer with functions to solve a number of processing requirements. A quick look at the front panel shows that each channel provides a full range of signal level control facilities: a dedicated and tuneable de-esser section, a compressor section with comprehensive control of all main parameters and an AUTOmode option for general use, and finally a highly informative LED metering section that never leaves the engineer 'in the dark'.

The DPR-422 uses a unique internal architecture, pioneered on the classic DPR-402, which combines a double side-chain with a subtractor to eliminate the distortion, noise and unwanted side-effects found in conventional compressors.