Korg NAUTILUS Series - Ring Modulation

EXi: MOD-7 Waveshaping VPM Synthesizer
308
9. Experiment with different settings of Slider 7.
This controls the cutoff frequency of Filter A. This filter
isn’t processing the output of VPM Osc 1; it’s just affecting
the modulator signal going into VPM Osc 1. VPM Osc 1
itself is connected directly to the Output Mixer, bypassing
the filters.
Finally, note that all of the examples above used only a
single VPM Oscillator–just a fraction of the MOD-7’s
resources. You can process PCM through all six VPM
Oscillators, in serial or parallel. For an example of this, listen
to factory MOD-7 Program USER-B 049, “Dancing
Waveshapes.” This processes the PCM through all six VPM
Oscillators in parallel, including both VPM and
waveshaping. Each creates a different timbre, and
rhythmically triggered envelopes switch between them in
turn.
Ring Modulation
Ring modulation takes two input signals, and creates new
frequencies based on those inputs. It can create everything
from subtle brightening effects to wild, dissonant, gong-like
timbres.
In the MOD-7, each VPM Oscillator includes a ring
modulator. You can use this to process any combination of
VPM, PCM, noise, and real-time audio input. You can also
modulate the wet/dry crossfade of the ring modulator, in
real-time.
For more information, see “5–4e: Ring Modulator” on
page 333.
Subtle motion
Let’s first look at a subtle use of ring modulation, to create
some motion in a simple sawtooth timbre.
1. Follow the instructions under “Creating an initialized
MOD-7 Program” on page 301.
To start, we’ll create an envelope for modulation:
2. Go to the EG3 page.
3. Set the Attack Time to 70, and the Decay Time to 90.
4. Set both the Break and Sustain Levels to 00.
Next, let’s connect VPM Osc 2 to VPM Osc 1:
5. Go to the Patch Panel.
6. Connect VPM Osc 2’s Output to VPM Osc 1’s
Input 1.
7. Go to the VPM Osc 2 page.
8. Set the Ratio to 2.
9. In Parameter Details, set Pitch Modulation AMS1 to
EG3, and set the Intensity to +00.10.
This small amount of pitch modulation will create a more
subtle ring modulation effect.
10.Go to the VPM Osc 1 page.
11.Set the Mode to Saw.
12.Set Input Level 1 to 0.
This means that VPM Osc 2 will only affect the ring
modulator.
13.Set the LPF to 50.
14.Play the keyboard; so far, this is a simple sawtooth
sound.
15.On the VPM Osc 1 page, select the Ring Mod
Crossfade parameter.
16.In Parameter Details, set the Crossfade AMS to EG3,
and the Intensity to 100.
Now, EG3 is doing two things: it’s changing the pitch of
VPM Osc 2, and fading the ring modulation in and out.
Together, this creates a fluttering, rolling effect.
Attack transient
Next, we’ll use ring modulation to create an attack transient.
Continuing from the above:
1. Go to the EG3 page.
2. Set the Attack Time to 00, and the Decay Time to 40.
3. Go to the VPM Osc 2 page.
4. Set the Mode to Saw.
5. Set the LPF to 60.
6. Select the Ratio parameter.
This makes the Pitch Modulation parameters appear in the
Parameter Details area.
7. Change the AMS1 Intensity to +02.00.
This will result in a stronger ring modulation effect.
8. Go to the VPM Osc 1 page.
9. Set the Mode to Sine.
This makes the effect of the ring modulation more obvious,
when crossfaded in and out.
10.Play the keyboard.
Now, the ring modulation is creating a chiff at the start of the
note.
Extreme sweep
For a more surreal ring modulation effect:
1. Go to the EG3 page.
2. Set the Decay Time to 80.
3. Go to the VPM Osc 2 page.
4. Set the Ratio Fine to +0.002.
This will create a little motion in the sustained sound, after
the initial sweep is complete.
5. Go to the VPM Osc 1 page.
6. Set the Mode to Saw.
7. Set the Ring Mod Crossfade to Ring Mod.
8. In Parameter Details, set the AMS Intensity to 000.
Now, the output will contain only the ring mod sound.
Previously, the sound had crossfaded between the dry and
ring mod timbres.
9. Play a chord on the keyboard, and hold it until the
sound settles.