Sequential Prophet VS - Page 124

124
STEEL DRUM (#l 6)
This program makes good use of the mixer envelope to produce a steel
drum sound which is consistent across the VS's 5-octave keyboard. Velocity
modulation of the oscillator mix adds to the program's realism by controlling
the "metallic" component of the sound.
Keyboard Mode
The program is in Single mode, although it doubles nicely with program #24
"CARIBEAN."
Oscillator Group
Oscillator A uses wave #35, which emphasizes the tenth harmonic. Oscillators
B and C use waveforms #32 (sine wave) and #33 (sawtooth), neither of which
emphasize one harmonic more than the fundamental. Oscillator D uses
waveform #114 which contains healthy amounts of the eighth and thirteenth
harmonics.
Filter
The lter cuto is set low, allowing the lter envelope to drive it higher with
increasing key velocity. To help accentuate the cuto frequency as it is swept
by the envelope, Resonance is set to 5.
Envelope Group
The mixer envelope moves quickly —and in roughly a straight line— from
oscillator A to a blend of oscillators C and D. Oscillator B, is brought up in
the mix momentarily as the envelope moves through point 1, but makes little
contribution to the program as it produces a sine wave at concert pitch. On
the other hand as points 2 and 3 (virtually identical) are approached, the
detuned eighth harmonic produced by oscillator D beats against oscillator C,
which is at concert pitch. As the lter cuto rises with increasing key velocity,
the thirteenth harmonic present in oscillator D becomes more evident, and the
program takes on a metallic quality.
When keys are released, and the mixer envelope enters its nal stage, the mix
gradually approaches a balance between all oscillators, and the program's
tone becomes smoother.
Both the amplier and lter envelopes are set for percussive initial decays
to point 3 (sustain level), but the lter envelope has a slightly slower attack,
delaying the entrance of oscillator A's tenth harmonic before the mixer
envelope shifts the emphasis to oscillators C and D.
LFO Group
Both LFOs are triangle waveforms at similar rates, but only LFO 1 is used in
the Modulation group.
HOME

BACK