This blanket term is applied to most common synthesizer configuration pioneered by East Coast based companies such as Moog, Arp, and EML (as well as “Far East” companies such as Roland and Korg) where one or more oscillators producing waveforms with rich harmonic content (such as a sawtooth or square wave) are fed into a filter that removes some of those harmonics, and then onto an amplifier to shape the loudness of a note. This approach is also often known as subtractive synthesis, as the filter reduces (subtracts) harmonics that came from the oscillators. East Coast synthesizers also regularly have organ-style black & white keyboards, and four stage ADSR type envelopes. Today it’s common to mix both East Coast and West Coast approaches in the same system.
Similar:
East Coast approach