Operation Manual

6.66 Polyvkey 126
6.66 Polyvkey
Similar to the Polykey module except that there is an additional output which
is proportional to the velocity with which the key was pressed. The stretch knob
on the interface is used to simulate stretched tuning used on instruments such as
pianos. Turned to the left, low notes will be tuned higher and high notes lower
(inner stretch); turned to the right, low notes will be tuned lower and high notes will
be higher (outer stretch). In the center position, the tuning will be equal. The error
knob introduces some randomness in the pitch signal. Turned to the left, no error
is outputed and the pitch signal is perfect; as the knob is turned to the right, errors
will start to appear causing small fluctuations in pitch. The effect of this knob is to
simulate pitch variations found in analog synths. The velo knob adjusts the velocity
curve of the Polyvkey. In the center position, the curve is linear. Turned to the left, the velocity
increases more quickly; conversely, turning the knob to the right results in a slower velocity curve.
The default value of the following parameters is set at construction
• pitch wheel range: determines the range of pitch variations that can be obtained with the
pitch wheel. The convention is 1 Volt/octave (maximum value is 2 Volts). A semitone is
equal to a 0.08333 value.
• MIDI channel: MIDI channel used by the keyboard.
• number of voices: number of voices requested for the modules enclosed within a Polykey
and Polymixer module.
Note: see also the Keyboard, Vkeyboard and Polykey modules.
6.67 Portamento
The Portamento module is an integrator and is used to smooth a signal. The
module has two inputs: a gate signal which turns it on or off, and the signal to be
smoothed. The output of the Portamento is the input signal smoothed according
to the time constant set by the glide knob. The higher the time constant, the slower
the response of the Portamento.
When the front panel on/off switch is on, the gate signal is ignored and the
input signal is always smoothed. When the switch is off the input signal is only
smoothed if the gate signal is greater than 0.1 Volt, otherwise the output is a copy
of the input. The following figure shows the Portamento behavior.