[2] The internal circuitry of Dolby A noise reduction, introduced in 1965, contained parallel buses with compression on one of them, the two mixed in a flexible ratio.
[2] In October 1977, an article by Mike Beville was published in Studio Sound magazine describing the technique as applied to classical recordings.
[4] A follow-up article by Richard Hulse in the April 1996 Studio Sound included application tips and a description of implementing the technique in a digital audio workstation.
If the normal analog method is used for a digital compressor, the signals traveling through the parallel pathways will arrive at the summing mixer at slightly different times, creating unpleasant comb-filtering and phasing effects.
Unusually extreme implementations have been achieved by studio mix engineers such as New York-based Michael Brauer who uses five parallel compressors, adjusted individually for timbral and tonal variations, mixed and blended to taste, to achieve his target sound on vocals for the Rolling Stones, Aerosmith, Bob Dylan, KT Tunstall and Coldplay.
[7] Mix engineer Anthony "Rollmottle" Puglisi uses parallel compression applied conservatively across the entire mix, especially in dance-oriented electronic music: "it gives a track that extra oomph and power (not just make it louder—there's a difference) through quieter portions of the jam without resorting to one of those horrific 'maximizer' plugins that squeeze the dynamics right out of your song.