The bottom half of the ES2 features LFOs and Envelopes.
LFO is an abbreviation for low frequency oscillator. As the name suggests, this is an oscillator, but different to the three oscillators in the top section of the ES2:
The LFO generates signals below the audio frequency range, between 0.1 and 20 Hz, but sometimes as high as 50 Hz. as it cannot be heard, it serves simply as a modulation source for periodic, cyclic modulation effects and does not form part of the actual audio signal.
LFO 1 is polyphonic and can work on multiple voices and is key-synced, so each time a key is played, the modulation starts from zero.
LFO 2 is monophonic, so the modulation is identical for all voices and when a chord is played on the keyboard, the pitch of all voices in the chord will rise and fall synchronously.
To further explain the LFO 1, The EG slider arrowed above is used to control the time taken for the LFO modulation to fade in and out. The Rate slider to the right, controls the frequency in hertz of the LFO 1 modulation. The value is displayed in Hertz (Hz) beneath the slider. The Wave buttons arrowed are used to select the desired waveform for LFO 1.
LFO 2, The Rate slider arrowed is the parameter that specifies the frequency in hertz or speed or speed e.g 1/64th of the LFO 2 modulation. LFO 2 rhythmic modulation effects will retain perfect synchronicity, even when the project tempo changes.
Working with Modulation
The following areas have been arrowed above as they play an important role in modelling different sounds and effects:
The Modulation Router does what it says, routes things you want to effect via the object you want to effect it with. The router links modulation sources like the envelope, to the modulation targets such as the oscillators and filters. There are 10 modulation routing columns.
The Modulation sources include the LFOs and envelopes.
The Vector Envelope is a sophisticated, loop-capable, multipoint envelope that can control the Planar Pad and Triangle (i.e the oscillator mix options). The Vector Envelope shapes the sound and can be viewed by clicking the Vector Envelope button to the right of the router.
Planar Pad: The Planar Pad is a controller that enables the simultaneous manipulation of two, freely assignable, parameters and is available as viasources as well, enabling you to control modulation intensities with them. It can be controlled with the Vector Envelope.
Modulation Target can be connected to any Modulation Source, rather like a studio patch bay.
Modulation Intensity is set with a slider and affects the extent to which the target is influenced by the source. Once a value other than off has been selected for a Via, the Intensity slider which is divided into two halves, becomes available, with the lower half defining the minimum modulation intensity and the upper half defining the maximum modulation intensity. The area between the two slider arrows is the modulation range of the via controller. The O in the centre of the vertical router is the zero intensity point. Finally, the via effect can be inverted by clicking on the invert area.
Ten modulation routings are available for source, via and target and these can operate simultaneously. Any of the ten modulation routings can be used and it is possible to select the same target, sources and controllers in multiple modulation routings.
A common sound setting is to use the modulation wheel on a keyboard to control the modulation intensity. Setting the router as below with target = pitch 123, Via = ModWhl, Source = LFO1
The Modulation intensity slider position can be played with to get the desired amount of modulation and the LFO 1 settings to modulate the frequency or pitch of the three oscillators (Pitch 123). This gives a vibrato effect, the depth of which can be further controlled with the mod wheel on the keyboard.
The Vector Envelope
The Vector Envelope allows for real-time control of the square icon movements in the Triangle and the Planar Pad. Whilst the Vector Envelope shares the same space occupied by the modulation router, it can be viewed by clicking the Vector Envelope button to the right of the router.
The Vector Envelope button when switched on, allows the user to specify the target to be controlled: the Planar Pad and/or the Triangle. If switched off, control of these parameters can still be carried out manually
If Mix is selected, the Triangle, is controlled but not the Planar Pad.
If XYis selected, the Planar Pad is controlled but not the Triangle.
If Mix+XY is selected, both the Planar Pad and the Triangle are controlled.
A maximum of 16 points can be displayed on the time axis and each point can control both the square icon positions of the Triangle and the Planar Pad. Shift/click between two existing points to add additional points.
There are a minimum of three points, with Point 1 as the start point, point 2 as the Sustain point, and point three as the end point.
Any point can be declared the Sustain point by Clicking in the turquoise strip above the desired point.
Any point can be declared the Loop point by Clicking in the turquoise strip below the desired point.
The following Loop modes can be selected: Off, Forward, Backward, and Alternate:
In Off mode, the Envelope runs from start to end.
In Forward, the Envelope runs from the start to the Sustain point, then repeat that in a forward direction.
In Backward, the Envelope runs from the startof the Sustain point, then repeat that section in a backward direction.
In Alternate, the Envelope runs from the start to the Sustain point, switches to the Loop point, then back again to the Sustain point, alternating between backward and forward directions.
The cycle speed of the loop speed can be set and also synchronized with the project tempo.