Mode 12: Harmonic generator with built-in sequenced envelope
generator
This mode can generate a signal with 15 harmonic frequencies. Instead of the external envelope generator inputs, an
internal one is used, and its output is fed to a virtual delay line so that a maximum of 4 delayed envelope waveforms
can be used for modulating the harmonics. No external envelopes can be used in this mode, save the one that may
optionally be used for controlling the PM synthesis feature for all the harmonics through the
modulation 2
input.
The internal envelope generator only has control on the attack period of the envelope which is the most important to
the instrument timbral characteristics. The release period is fixed to a relatively rapid decay rate.
The knobs
adjust 1
and
adjust 2
are used for the envelope shape determination.
Adjust 1
controls weighing
between two alternative attack waveform shapes, the other a monotonously rising waveform, and the other a
sinusoidally varying, overshooting waveform. Figure 12.1 shows the resulting envelope shapes with the two
extreme adjustment cases when turning
adjust 1
, and one middle adjusted case.
The toggle switch has to be in the
gate on
position to trigger the envelopes.
adjust 2
is used to vary the speed of the envelope attack edge together with
Slider 16
. When turning
adjust 2
CW,
the speed is increased, i.e the attack period becomes shorter for both the monotonous and overshoot waveforms. It
also correspondingly compresses the periods between the 4 sequenced outputs. CCW rotation correspondingly
increases the durations of the envelopes.
Slider 16
is used as an adjustment for the trigger delays between the
internal envelope generator outputs. Raising the slider will increase the delay between the 4 sequenced outputs. The
total duration of the delay also depends on
adjust 2
that controls the speed to run through the delay.
All the sequenced waveforms will have identical shape, only their delay from the gate trigger is different. For all the
15 harmonics corresponding to the sliders, any of the 4 differently delayed, identical waveforms can be selected.
The selection is done exactly in the same way as selecting one of the external
envelope inputs
in the basic mode,
i.e. by turning the toggle switch down to the position "envelope select", and then moving the selected slider up and
down until one of the lit leds next to the 4
envelope inputs
shows the desired delay. The delay length corresponds
to the order number of the input, so if the led next to the input 1 is lit for the moved slider, the corresponding
harmonic has zero delay; if it is lit next to input 2, it has 1/4th part of the total delay, and if next to input 4, it has the
maximum delay. Returning the toggle switch back up, will activate and store the corresponding delay setup in the
nonvolatile memory.
Similarly to the basic mode, when you power the system up, all delays default to 0, corresponding to input 1, and
only when you momentarily flip the toggle switch down and again up, the stored delay setup is recalled.
Because no external envelopes are used, you need to keep the toggle switch turned up, in the
gate on
-position for
playing in order to get the note start trigger signal, the gate signal, for the envelope generator. Note that the gate
trigger signal has to be connected from an external source..
An optional input can be used for
modulation 2
. It controls the phase modulation of all the harmonics equally. With
zero voltage or no input, there is no modulation, and all the harmonics are pure sinusoids. There is no other control
of the modulation strength like in the basic mode, so for this input, you probably will like to use an external
envelope generator with good amplitude control, because the maximum voltage level of about 6 volts will make an
extremely spectrally rich modulation result.
Tip:
One example of acoustic instrument -type sounds is generated when you have a
djust 1
fully CCW,
adjust 2
turned to make a pretty rapid transient, and a fast attack-decay envelope connected to
modulation 2
. The resulting
sound is close to trumpet, because the fast tremolo from the overshooting amplitude envelope resembles the player
lip action, and the short PM modulation during the attack period makes an effect that is somewhat similar to the
trumpet spectrum variation.
As a summary, here is a list of controls and the patch cable connections required for Mode 12:
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