Yamaha SY77 - Synthesis Technologies

Synthesis Technologies

The AFM synthesis of the SY77 is effectively a superset of the 6-operator FM synthesis available on the Yamaha DX7 and DX7 II series of synthesizers. With a few minor exceptions, it is capable of all of the sounds that can be produced by those earlier keyboards – with various programs being able to automatically translate DX patches intelligently into accurate SY equivalents – and many more sounds besides. Among the advantages of AFM synthesis over FM synthesis are: a larger choice of algorithms, 15 additional waves besides the standard sine, which have additional harmonic content; and the flexible routing of up to three feedback sources within any algorithm, as opposed to the DX series' small number of fixed algorithms with a single source each.

The SY/TG series also introduced Yamaha's now-flagship Advanced Wave Memory (AWM) technology for playback and manipulation of PCM samples. Such waveforms can be used as samples alone or, in two features specific to the SY/TG series, can be used as transients to FM-synthesized main waveforms (similar to Roland's LA synthesis) or, via RC&M (Real-time Convolution and Modulation), used as modulators for FM operators in place of elementary signals like sine and sawtooth waves.

These technologies, both alone and in combination, can generate rich, layered, multi-timbral sounds, and there are large libraries of patches available for it. Sound sets on floppy disks are available online with patches and presets ranging from emulationis of classic synthesizers and ambient pads, to percussion and organ sounds. A single 720 kB (DD) formatted floppy disk can hold over 400 patches.