Korg NAUTILUS Series

PROGRAM > MOD-7: Oscillator 5–4: VPM Osc1
327
one random value, and those for EXi2 would have another.
To get the vintage DX7 behavior, set oscillators to Free Run
and set their phase to 0.
Feedback [0…100]
Feedback is a third FM input, hard-wired in one of two
ways to the oscillator’s own output, which allows the
oscillator to modulate itself. The exact routing depends on
the Feedback Path parameter; for more information, see
“Feedback Path” on page 327.
Feedback is available only when Mode is set to Sine or
Sine + Waveshaper.
With Feedback Path set to From Sine Osc, setting
Feedback to 65 creates a reasonable approximation of a
sawtooth waveform. Modulation of Feedback will then
sound similar to modulating the cutoff frequency of a low-
pass filter.
Pitch Parameter Details
These items appear in the Parameter Details area when
Ratio, (Ratio) Fine, Freq Offset, (Freq Offset) Fine, Initial
Phase, or Phase Sync are selected.
Note: When both Ratio and Ratio Fine are set to 0, pitch
modulation will have no effect.
Use Common Mod [Checkbox]
On: The oscillator will respond to all of the pitch modulation
from the Osc Main page. This the default.
Off: The oscillator will ignore the Osc Main page’s LFO
and AMS settings. It will still respond to the Pitch and
Portamento settings, including Pitch Slope, JS (+X), JS(–
X), and Analog. It will also respond to all pitch-related EXi
Common parameters, such as Chord and Scale.
AMS1 [List of AMS Sources]
This selects the first modulation source for controlling the
oscillator’s pitch. For a list of AMS sources, see “Alternate
Modulation Source (AMS) List” on page 901.
Intensity [-48.00…0.00…+48.00]
This controls the depth and direction of the AMS 1 pitch
modulation, in semitones. To easily convert from semitones
to FM ratios, see the table below.
AMS1 Int. Mod [List of AMS Sources]
You can modulate AMS 1’s Intensity from another AMS
source. This selects that source.
Intensity [-48.00…0.00…+48.00]
This controls the depth and direction of the Intensity Mod
AMS, in semitones. The result is summed with the main
AMS 1 Intensity to produce the final pitch modulation
amount.
AMS2 [List of AMS Sources]
This selects a second modulation source for controlling the
oscillator’s pitch. For a list of AMS sources, see “Alternate
Modulation Source (AMS) List” on page 901.
Intensity [-48.00…0.00…+48.00]
This controls the depth and direction of the AMS 2 pitch
modulation, in semitones.
Feedback Parameter Details
These items appear in the Parameter Details area when
Feedback is selected.
Feedback Path [From Sine Osc, From Output]
This controls the source of the Feedback signal.
From Sine Osc routes the feedback directly from the output
of the Sine Oscillator. The rest of the VPM Oscillator signal
chain, including the LPF, HPF, waveshaper, ring modulator,
and output volume control, will not affect the feedback. Use
this option when you want the feedback timbre to be
independent from the output volume.
From Output routes the feedback from the output of the
entire VPM Oscillator signal chain. When the Oscillator
Mode is set to Sine, this produces the feedback structure of
classic FM synths.
Feedback Path
AMS [List of AMS Sources]
This selects an AMS source to control the Feedback. For a
list of AMS sources, see “Alternate Modulation Source
(AMS) List” on page 901.
Intensity [–100…+100]
This controls the depth and direction of the AMS modulation
for Feedback.
Ratio Pitch in semitones
1Root pitch
2 +12.00
3+19.01
4 +24.00
5+27.83
6 +31.03
7 +33.44 -- 2 octaves + minor seventh (-56 cents)
8 +36.00
9 +38.09 -- 3 octaves + whole tone (+9 cents)
10 + 39.65 -- 3 octaves + major third (-35 cents)
12 +43.06 -- 3 octaves + fifth (+6 cents)
15 +46.50 -- 3 octaves + major seventh (-50 cents)
16 +48.00
Sine Osc LPF W aveshaper HPF Ring Output
Feedback = From Output
Feedback = From Sine Osc