The article seems to elide the differences between subtractive synths, and all the many other forms of synthesis--Frequency Modulation, Additive (Fourier), Phys

The article seems to elide the differences between subtractive synths, and all the many other forms of synthesis--Frequency Modulation, Additive (Fourier), Physical Modeling, and others that don't necessarily have all the pieces they mention like filters and VCAs. The DX7 has 6 digital oscillators that can only produce sine waves and no filter. It functions very differently form subtractive synths, but is capable, with only six sines, of creating sounds that have far more complex harmonics (and non-harmonic tones) than most subtractive synths.