The so-called “West Coast” approach to synthesis – traditionally associated with companies such as Buchla and Serge – is often based around adding harmonics to simple waveforms, rather than removing (filtering) them from complex waveforms. This is often accomplished by using a pair of oscillators (sometimes combined into what’s called a “complex oscillator”) where one modulates the frequency (FM) or amplitude (AM) of the other; another common West Coast module is a waveshaper or a wavefolder. You may also find two-stage envelope generators such as an AD or AR (often called slope generators) rather than four-stage ADSRs, as well as more of an emphasis on control voltage manipulation, A common feature is also voltage controlled amplifiers that have low-pass filters built into them, creating what’s known as a Low Pass Gate (LPG). The West Coast approach also embraces non-traditional controllers, such as touch plates and the such. Today it’s common to mix both East Coast and West Coast approaches in the same system.
