Yamaha SY99 Owner's Manual page 24

Two realtime digital
filters for each element
AFM x AWM x Filtering =
the SY99
Play up to 16 AFM notes
and 16 AWM notes at
once
A Drum voice consists of
76 percussive sounds
The one, two, or four elements in a voice can produce many types of keyboard
split and layer effects.
On earlier Yamaha synthesizers such as the DX7-II, layers and splits were
created by combining two or more Voices into a "Performance". This meant that
sometimes you played Voices and other times you played Performances.
However on the SY99, layers and splits can be included in a voice, so you can
simply select a voice and play without considering whether it contains layers or
splits.
Each AFM or AWM element in a voice includes two 12 dB/octave realtime digi-
tal filters, each filter independently controlled by its own envelope generator
(EG). One filter is fixed as a Low Pass Filter (LPF) and the other filter can be
used either as a LPF or a High Pass Filter (HPF). This allows you to use the
two in conjunction to create a 12 dB/octave Band Pass Filter (BPF) or a 24
dB/octave LPF. Veterans of analog synthesizers will be happy to hear that the
filter resonance (or "Q") can be adjusted all the way into filter oscillation.
Since a voice can consist of one, two, or four elements, a single voice can
use 2, 4 or 8 independent filters.
The SY99 can utilize most of the programming techniques of previous synthe-
sizers; FM, sample playback, and realtime filtering. This means that the SY99
can produce the sounds of the classic 24 dB/octave analog synthesizers of the
past, the FM sounds of the DX series, the sampled sounds of many of today's
instruments ... and also sounds that have never been heard before.
The SY99 contains two tone generators; an AFM tone generator and an AWM
tone generator. The AFM tone generator can produce up to 16 simultaneous
notes of FM sound, and the AWM tone generator can produce up to 16 simul-
taneous notes of digitally sampled sound.
Some voices consist of only one element, some of two elements, and others
of four elements. (The Voice mode setting inside each voice determines how
many elements are used.) The important thing to remember is that up to a total
of 16 notes of AFM sound and 16 notes of AWM sound can be sounding at any
time. If a voice plays two or more elements for a single key, the sound will be
more complex and richer, but you will be able to play fewer simultaneous notes.
In addition to the "normal" voices explained above which consist of one, two, or
four elements, the SY99 provides a special type of voice; the Drum voice.
A drum voice has no elements, but consists of a different AWM sample for each
of the 76 keys of the SY99 keyboard.
A drum voice can be played from the keyboard just like a normal voice.
Usually you will use a sequencer to play a drum voice, providing drums and per-
cussion accompaniment. Either the SY99's internal sequencer or an external
MIDI sequencer can be used to play a drum voice.
There is no distinction between normal voice memory and drum voice mem-
ory; either type of voice can be stored in any of the voice memories.
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