Operation Manual

SUBTRACTOR SYNTHESIZER
117
LFO Section
LFO stands for Low Frequency Oscillator. LFOs are oscillators, just like Osc 1 & 2, in
that they also generate a waveform and a frequency. However, there are two signifi-
cant differences:
• LFOs only generate waveforms with low frequencies.
• The output of the two LFOs are never actually heard. Instead they are used for
modulating various parameters.
The most typical application of an LFO is to modulate the pitch of a (sound generat-
ing) oscillator, to produce vibrato. Subtractor is equipped with two LFO’s. The param-
eters and the possible modulation destinations vary somewhat between LFO 1 and
LFO 2.
LFO 1 Parameters
Waveform
LFO 1 allows you to select different waveforms for modulating parameters. These are
(from top to bottom):
Destination
The available LFO 1 Destinations are as follows:
Sync
By clicking this button you activate/deactivate LFO sync. The frequency of the LFO
will then be synchronized to the song tempo, in one of 16 possible timedivisions.
When sync is activated, the Rate knob (see below) is used for setting the desired ti-
medivision.
Turn the knob and check the tooltip for an indication of the time division.
Rate
The Rate knob controls the LFO’s frequency. Turn clockwise for a faster modulation
rate.
Amount
This parameter determines to what degree the selected parameter destination will be
affected by LFO 1. Raising this knob’s value creates more drastic results.
|Waveform |Description
Triangle This is a smooth waveform, suitable for normal vibrato.
Inverted Saw-
tooth
This produces a “ramp up” cycle. If applied to an oscillator’s fre-
quency, the pitch would sweep up to a set point (governed by the
Amount setting), after which the cycle immediately starts over.
Sawtooth This produces a “ramp down” cycle, the same as above but in-
verted.
Square This produces cycles that abruptly changes between two values,
usable for trills etc.
Random Produces random stepped modulation to the destination. On some
vintage synths, this is called “sample & hold”.
Soft Random The same as above, but with smooth modulation.
|Destination |Description
Osc 1&2 Selecting this makes LFO 1 control the pitch (frequency) of Osc 1
and Osc 2.
Osc 2 Same as above, but for Osc 2.
Filter Freq Selecting this makes the LFO 1 control the filter frequency for Filter
1 (and Filter 2 if linked).
FM Selecting this makes the LFO 1 control the FM Amount parameter.
Both oscillators must be activated for this to have any effect.
Phase Selecting this makes the LFO 1 control the Phase Offset parameter
for both Osc 1 and 2. Note that Phase Offset Modulation (Subtrac-
tion or Multiplication) must be activated for this to have any effect
(see page 110).
Osc Mix Selecting this makes the LFO 1 control the oscillator Mix parameter.