LFOs

As well as a simple, dedicated LFO for the mod wheel (described for the keyboard panel) there are three complex LFOs.

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LFO1

LFO1 is a polyphonic LFO with the following waveforms available at all modulation destinations:

  • Parabolic - Symmetry controlled by shape knob.
  • Triangle/saw - Symmetry controlled by shape knob, with center position providing triangle; left is down saw; right is up saw. Note that the bimodal modulation matrix permits inversion of these waveforms at different destinations.
  • Pulse - Width ratio controlled by shape knob.
  • Sample and hold - The triangle/saw waveform is sampled when the amplitude envelope restarts for each voice.
  • Down ramp - A saw waveform that is unaffected by the position of the shape knob.

The LFO1 panel provides the following controls:

Freq

The vertical axis of this XY control sets the base frequency of the LFO. The current level for each voice is displayed as horizontal lines within the XY control. The horizontal value for the XY control has no effect.

Shape

Controls the width ratio of the parabolic, triangle, and pulse waveforms. When centered, the output waveforms are symmetric. The shape knob has no effect on the ramp down waveforms.

Spread

Spreads the frequency of the LFO to a different value for each voice. When fully turned left, the LFO2 for all voices have exactly the same frequency. At higher settings, LFO frequency is different for each voice. See the instrument tooltips for more specific information.

Sync

When enabled, the LFO restarts for each voice when the amplitude envelope restarts for that voice.

LFO2

LFO2 is a monophonic LFO with the following waveforms available at all modulation destinations:

  • Parabolic - Symmetry controlled by shape knob.
  • Triangle/saw - Symmetry controlled by shape knob, with center position providing triangle; left is down saw; right is up saw. Note that the bimodal modulation matrix permits inversion of these waveforms at different destinations.
  • Pulse - Width ratio controlled by shape knob.
  • Ladder - The triangle/saw waveform is sampled at a periodic interval and held, generating either an ascending staircase, descending staircase, or ziggurat waveform.
  • Random - A noise source is sampled at various intervals. The range or randomness for the noise source can also be controlled.
  • Up Ramp - An inverted saw waveform that is unaffected by the position of the shape knob.
  • Down ramp - A saw waveform that is unaffected by the position of the shape knob.

The LFO1 panel provides the following controls:

Freq

The vertical axis of this XY control sets the base frequency of the LFO. The XY control also displays the current output value as a horizontal line. The horizontal value for the XY control has no effect.

Shape

Controls the width ratio of the parabolic, triangle, and pulse waveforms. When centered, the output waveforms are symmetric.

For the staircase waveforms, the shape knob controls whether the ladder steps up, down, or in both directions. When centered, the output steps up and down at the same rate. At other values the up/down frequency is distorted.

Step

For the ladder waveform, controls the number of steps within each LFO cycle. For the random waveform, controls the range of randomness.

Sync

When enabled, the monophonic LFO restarts when the amplitude envelope restarts for any voice.

Tempo LFO

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The tempo LFO operates at a fixed ratio of the clock period, and additionally provides controls for fading in and fading out the LFO waveform. If desired, the fade-in and fade-out can be used as an additional envelope.

The following waveforms are available from the tempo LFO as modulations:

  • Sine - Actually a parabolic waveform with symmetry controlled by shape knob.
  • Linear - Triangle/Saw waveform with symmetry controlled by shape knob: center position is triangle; left is down saw; right is up saw. Note that the bimodal modulation matrix permits inversion of these waveforms at different destinations.
  • Pulse - Width ratio controlled by shape knob.

The Tempo LFO has the following controls:

Freq

The vertical axis of this XY control simply displays the current level for each voice as horizontal lines. This XY strip provides no control functionality.

Tempo

Sets the frequency of the LFO as a multiple of the global clock. If set to ENV only, the tempo LFO functions purely functions as an AR envelope.

Attack

Sets the fade-in time of the LFO as a multiple of the global clock. When set to 0 , the fade-in is disabled. With other values, the amplitude of the LFO linearly increases, reaching unity gain at set tempo period.

Release

Sets the fade-out time of the LFO. this is similar to the Attack , but fade out commences when the gate signal for a voice drops to zero.

Shape

Controls the width ratio of all the tempo LFO waveforms. When centered, the output waveforms are symmetric.

Sync

When enabled, the LFO phase resets for each voice when the amplitude envelope restarts for that voice.

Envelopes

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There are two standard ADSR envelopes (as well as an AR envelope in the tempo LFO).

The amp envelope is also available as the Envelope 1 modulation source throughout the instrument. Envelope 2 is also available as a general modulation source. For both envelopes, modulation is available with gate set to a fixed value of 1 (so that the envelope has a uniform gain), and with gate set to velocity (so that envelope gain tracks velocity).

The envelopes both display the current waveform for the envelope of voice 1 (the envelope for each voice may be different, depending on the settings). In addition, the envelopes provide the following controls, including some special controls inspired by the BTS synth in the Reaktor library:

A

Attack time.

D

Delay time.

S

Sustain time.

R

Release time.

vel

Scales envelope 1 velocity throughout the instrument. In its center position, velocity is exactly that received. When turned full right, velocity is twice that received. turning this knob left of center causes the relative difference in velocity values to decrease. When turned full left, velocity is fixed at 0.5.

p>e

Pitch to envelope scaling. When this knob is in its center position, pitch has no effect on the envelope shape. When this knob is to the right of center, pitch of higher notes increase the attack, decay, and release of the envelope (lengthening the envelope shape). When to the left, higher notes shorten the overall envelope shape.

v>a

Velocity to attack-time scaling. When this knob is in its center position, velocity has no effect on the attack time. Higher values cause higher velocities to increase attack time; lower values cause higher velocities to reduce attack time.

Modulation Routing

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A switchless modulation matrix permits the selection and adjustment of many different modulation sources. The architecture uses a similar design for all modulation destinations. As summarized in the above diagram, modulation routing is as follows:

    • There is a large XY control to set a base value (prior to modulation) for one parameter horizontally, and another parameter vertically.
    • The XY control also displays the current values for all voices (shown as crosses or rectangles, depending on the parameter).
    • The sliders and associated screen controls constrain and modulate the parameter. There are a standard set of generic controls for each modulation target:
    • A Range bar
    • A Clip button
    • Gain and Curve knobs
    • One pitch tracking slider ( P )
    • Four modulation sliders ( A , B , C , and D )
    • Four modulation source list boxes ( A , B , C , and D )
    • Two Value displays.

The following screenshot labels the above controls for the vertical parameter of an XY panel.

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The following subsections describe the above generic controls.

X Value and Y Value

By default, these two numeric displays show the current value of the X and Y parameters of the large XY panel.

After moving any slider or knob associated with this XY panel, the instrument displays the most recent value of the slider or knob in these status meters, for a short period. When adjusting the range slider, these controls show the minimum and maximum range for a short period. After the short period, the numeric displays revert to showing the current XY panel values.

Modulation amounts are always shown as percentages.

These two meters save a significant amount of screen real estate over displaying the specific value for every single slider or knob, and at the same time provide the same amount of useful information.

Range

You can adjust the position of both ends of the Range bar. The bar position is saved with the snapshot, and also through some special circuitry, the previous bar positions upon exit/restart are properly restored.

The Range bar is important, because it absolutely limits the output range. For example, if the ends of the bar are set at 0.5 and 1.0, then the output value will always be between 0.5 and 1.0, regardless of gain and modulation amounts. Also, XY values and modulation amounts are scaled by the range. For example, if the range is set to between 0.5 and 1.0, then placing the crosshair in the middle of the XY panel sets the base value to half way between 0.5 and 1.0 (which is 0.75).

Restricting the range is useful, for example, when you wish to stop very high resonance values; simply restrict the resonance range accordingly.

The gain, the modulation amounts, and the base XY values are all scaled by range settings. This means you can easily "zoom in" on a particular zone (perhaps particular filter frequency and resonance ranges), and obtain very fine control of the base value and modulations within that range.

Gain

The gain knob scales the modulations (A, B, C, D, and P). For example, if the range is 0 to 1, and a modulation's amount is 25%, then setting gain to 1 yields a modulation amount of 25%; setting gain to 2 yields a modulation of 50%; and so on.

When you change the range settings, the gain is scaled proprotionally. However, you can still set gain so that modulations intentionally exceed the range. This lets you intentionally clip or mirror the modulations.

Clip/Mirror

When the Clip button is on, the output value is clipped within the set range.

When off, the modulations are instead mirrored using a fully recursive algorithm, best shown in an illustration (see below). On the left, the modulation amount is within the range settings, so it passes through without change. The middle waveform shows what happens if the upper range is slightly lower: when the modulation exceeds the upper range, the output's mirrored once. On the right, you can see what happens if the upper range is lowered even more. When the source first exceeds the upper range, it gets mirrored just once; then when the modulation is so large that the mirrored value exceeds the lower range, then it gets mirrored again (recursive mirroring):

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This permits many interesting sound possibilities, with multiple modulations bouncing around.

Curve

Pitch Tracking

For the pitch tracking slider (P), behavior is different depending on the destination:

  • For oscillator pitch and filter frequency, the center position causes pitch to track uniformly with the source pitch (at unity gain). At higher values, higher pitches are greater and lower pitches are less. At lower values, the pitch is reversed, so that higher pitches result in a lower value, and vice versa.
  • For destinations besides pitch and frequency, there is no modulation by a note's pitch value when the P slider is in its center position. At higher values for the P slider, higher note pitches increase the output value. At lower values, higher note pitches reduce the output value.

Modulation Sliders

The four modulation sliders (A, B, C, and D) set the amount of the modulation applied to the target from the selected modulation source.

For all modulation sliders, the center position is neutral (off). All modulations are bipolar. This means the modulation may be positive or negative, depending which way you move the slider.

Modulation List Boxes

These lists select a modulation source for each slider, arranged in a stack. The top list box chooses the modulation source for slider A, the next one chooses the modulation source for slider B, and so on.

Note that these list boxes are, in Reaktor terms, "lists" and not "switches." Changing any modulation source does not interrupt the sound. All modulation sources are available throughout the instrument without using any switches!

A and B are polyphonic sources; C and D are monophonic sources. There are 15 sources for each, described in the following tables.

Polyphonic Sources

E1

E2

Envelope 1 and 2.

V1

V2

Envelope 1 velocity. Velocity remains at this value for each voice until the voice starts a new note.

L1D

L2D

LFO ramp down. The waveform is unaffected by the LFO's shape control, and is always a down ramp. Because all modulations are bipolar , the ramp down provides an inverted waveform of ramp up, within exactly the same range.

L1H

L2H

LFO sample and hold. The LFO1 "triangle" waveform is sampled when the envelope restarts for each voice.

L1S

L1S

LFO "sine". The waveform is actually parabolic and may be shaped by the LFO's SHAPE control.

L1P

L2P

LFO pulse. The pulse width ratio may be set by the LFO's SHAPE control.

L1T

L2T

LFO "triangle". The waveform may vary between a triangle and ramp, as set by the LFO's SHAPE control.

M1

Multiplier 1. See Multipliers.

OFF

Turns off the modulation source. This setting causes disables event processing for the source regardless of the position of the amount slider, resulting in some CPU savings.

 

Monophonic Sources

L2S

LFO2 "sine". The waveform is actually parabolic and may be shaped by the LFO's SHAPE control

L2T

LFO2 "triangle". The waveform may vary between a triangle and ramp, as set by the LFO's SHAPE control

L2P

LFO2 pulse. The pulse width ratio may be set by the LFO's SHAPE control

L2L

LFO2 ladder. The modulation source steps between a series of ascending or descending fixed values, with the number of values and direction determined by the LFO2 settings.

L2R

LFO2 random. The modulation source steps between random values, with the number of values and direction determined by the LFO2 settings.

L2U

LFO2 ramp up. The waveform is unaffected by the LFO's shape control, and is always an up ramp.

L2D

LFO2 ramp down. The waveform is unaffected by the LFO's shape control, and is always a down ramp. Because all modulations are bipolar , the ramp down provides an inverted waveform of ramp up, within exactly the same range.

WHL

Mod wheel value, between 0 and 1. See Mod Wheel.

BND

Bend value, between -1 and +1. This source merges input from external MIDI and the bend slider in the instrument's on-screen keyboard.

AFT

Channel aftertouch, between 0 and 1.

S1P

Sequencer 1 pitch, scaled between 0 and 1, with middle C at a value of 0.5. This monophonic source provides the most recent pitch from Sequencer A.

S1V

Sequencer 1 velocity, between 0 and 1. This monophonic source provides the velocity of the most recent note from Sequencer A.

S2P

Sequencer 2 pitch, scaled between 0 and 1, with middle C at a value of 0.5. This monophonic source provides the most recent step from Sequencer B.

S2V

Sequencer 2 velocity, between 0 and 1. This monophonic source provides the velocity of the most recent step from Sequencer B.

M2

Multiplier 2. See Multipliers.

OFF

Turns off the modulation source. Note: this setting causes the event processing for this modulation source to be disabled, resulting in a very small improvement in CPU utilization.

Multipliers

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The matrix multipliers provide selection of two sources. the sources are multiplied together and available throughout the instrument as a single modulation source.

Multiplier 1 can multiply together any two modulation sources, whether they are polyphonic or monophonic. Multiplier 2 can multiply together any two monophonic sources. For example, the M2 unit can multiply pitch bend by an LFO. Then the M2 source provides an LFO modulation source whose amount of modulation may be controlled by pitch bend.

Each multiplier panel has the following controls:

A

Selects the source A, which may be any polyphonic or monophonic source listed in the above tables. In addition, pitch tracking is available as a source; pitch tracking has a value between 0 and 1, with center pitch taken from the global pitch control panel.

To reduce CPU usage slightly, select the FIX source.

B

Selects the source B, same as for source A.

Exp

Each source may be exponentiated by turning on its respective exp button. An exponentiated source is simply the source value multiplied by itself (squared). Exponentiation is performed after scaling (by the scale factor) but before the two sources are multiplied together. If you just wish to exponentiate one source and not multiply it by another source value, then turn on exp for one source and select FIX for the other source.

Scale

Source A and source B may each be scaled by any factor. (Of course if neither A nor B is exponentiated, then the output is simply A*B*Ascale*Bscale).

Note: Be careful if using the matrix multiplier with the Osc3 contour or osc3 sync sources, because it is possible to set up an infinite loop that will crash Reaktor. For example, if a multiplier source is set as O3C, and one of the osc3 contour modulation sources is the matrix multiplier itself, then the events loop infinitely between the multiplier and O3C. (If you're concerned about this, you can delete the connection to O3C and O3S from the matrix multiplier's source connections, but sometimes this routing may be useful, so the connection is left in the current instrument structure).