9720 VCO 23
010321
change from one pitch to the next is perceptually instantaneous. At "max" full CW portamento
from one pitch to the next takes several seconds.
OscB PW.
This control sets initial Duty Factor of the
OscB Pulse output. At "min" the Pulse output is a
square wave (~50% DF). At "max" the output is a
narrow negative pulse (>95% DF)
MODULATOR CONTROLS
Trigger Input
- A transition from ground to 4V or
greater triggers the Modulator. Attack cycle
followed immediately by Release with no Sustain interval.
Gate Input
- A voltage greater than 4V gates the
modulator. Attack cycle is followed by Sustain for as
long as the Gate is present. Release when Gate returns to ground.
A-R
- The normal Attack (Sustain) Release
function of the modulator.
Cycle -
In this mode the Modulator self-triggers
for a Low Frequency Oscillator function. Repetition period is the
sum of the Attack and Release times. Cycle mode responds to a
true Gate input by interrupting the cycle with the output high.
Periodic Trigger pulses hard sync the LFO.
Output
- Amplitude of the Control Voltage from this
output is set by the Output control. The arrow
indicates that the Modulator Output is normalized to
the Pulse Width Modulation input of OscB. Inserting a plug does not
interrupt the normal.
Attack
- Sets the time required for the output to rise to it's peak level.
Time range is 500 uS (0.5 mS) at the CCW extreme to 6S when
the control is fully CW.
Release
- Sets the time required for the output to return to "zero".
Time range to return to less than 1V is 2mS at the CCW extreme
to 10S when the control is fully CW.
Output
- Sets the output Level. Range of control is 0V at the CCW
extreme and about 10V peak when the control is fully CW.
THE BLOCK DIAGRAM
Fig 6 in the illustrations supplement shows
the organization and normalization of the panel controls, inputs
and outputs.
Design Analysis
Response to G
Attack > Release
Attack < Release
LFO functions
Attack = Release
Trigger/Gate
LFO Sync / Gate
Response to T
Response to G
Trigger/Gate
Response to T
A-R functions
Calibrate Init Pitch for
R52 to calibrate to .8V
OscA LFO function vari
AR Cycle A= 1ms to 8s
Summary of Contents for 9720
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