David Blackmer founded dbx in 1971, based on the concept of using decibel expansion (hence the name "dbx") to replace the peaks lost from the limited dynamic range of magnetic tape. His brilliant decilinear VCA and RMS level detection circuits changed the world, yielding classic products such as dbx noise reduction, dbx compressors, OEM VCAs for automated consoles and more.
Blackmer’s first pro unit was the still highly regarded Model 160 compressor/limiter, something he really didn't want to make, because—after years of creating products that would restore or expand dynamic range—a box that squashed dynamics seemed very wrong to him. Yet this half-rack unit quickly found favor with engineers—particularly on drums—and two 160s could easily be linked for stereo operation. Other variants include the Model 161 (with unbalanced inputs) and the stereo-only Model 162, with a single set of controls.
Click mixonline.com/online_extras/blackmer_rms_patent.pdf to read David Blackmer's groundbreaking original patent on RMS level detection.
Click mixonline.com/online_extras/dbx_160.pdf to read an original dbx 160 user manual.