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Update: 2020-08-18

Table of Contents

LightPadSynth

LightPadSynth is a lightweight version of CubicPadSynth. For efficiency, interpolation is changed to linear. Also pitch modulation is omitted. Instead, a delay is added for each voice.

LightPadSynth requires CPU which supports AVX or later SIMD instructions.

The package includes following builds:

macOS build isn’t tested because I don’t have Mac. If you found a bug, please file a issue to GitHub repository or send email to ryukau@gmail.com.

Linux build is built on Ubuntu 18.0.4 and tested on Bitwig and Reaper. If you are using distribution other than Ubuntu 18.04, plugin will not likely run. In this case, please take a look at build instruction.

Installation

Plugin

Place *.vst3 directory to:

DAW may provides additional VST3 directory. For more information, please refer to the manual of the DAW.

Presets

Extract preset zip, then place preset directory to the OS specific path:

Preset directory name must be the same as the plugin. Make Uhhyou directory if it does not exist.

Windows Specific

If DAW doesn’t recognize the plugin, try installing C++ redistributable (vc_redist.x64.exe). Installer can be found in the link below.

Linux Specific

On Ubuntu 18.0.4, those packages are required.

sudo apt install libxcb-cursor0  libxkbcommon-x11-0

If DAW doesn’t recognize the plugin, take a look at Package Requirements section of the link below and make sure all the VST3 related package is installed.

REAPER on Linux may not recognize the plugin. A workaround is to delete a file ~/.config/REAPER/reaper-vstplugins64.ini and restart REAPER.

macOS Specific

When trying to run plugin first time, following message may appear on macOS.

<PluginName>.vst3 is damaged and can't be opened. You should move it to
the Trash"

In this case, open terminal and try running following command to unzipped .vst3 directory.

xattr -rc /path/to/PluginName.vst3

Plugin may be considered as unsigned/un-notarized application. In this case, try following the steps below.

  1. Open terminal and run sudo spctl --master-disable.
  2. Go to System Preferences → Security and Privacy → General → Allow apps downloaded from, then select “Anywhere”.

Beware that steps above degrades security of your system. To revert the settings, follow the steps below.

  1. Go to System Preferences → Security and Privacy → General → Allow apps downloaded from, then select option to “App Store and identified developers”.
  2. Open terminal and run sudo spctl --master-enable.

Reference

Color Configuration

At first time, create color config file to:

Below is a example of style.json.

{
  "fontPath": "",
  "foreground": "#000000",
  "foregroundButtonOn": "#000000",
  "foregroundInactive": "#8a8a8a",
  "background": "#ffffff",
  "boxBackground": "#ffffff",
  "border": "#000000",
  "borderCheckbox": "#000000",
  "borderLabel": "#000000",
  "unfocused": "#dddddd",
  "highlightMain": "#0ba4f1",
  "highlightAccent": "#13c136",
  "highlightButton": "#fcc04f",
  "highlightWarning": "#fc8080",
  "overlay": "#00000088",
  "overlayHighlight": "#00ff0033"
}

Hex color codes are used.

First letter # is conventional. Plugins ignore the first letter of color code, thus ?102938, \n11335577 are valid.

Do not use characters outside of 0-9a-f for color value.

Controls

Knob and slider can do:

There is an additional control for number sliders used for Octave, Seed etc.

Control with many blue vertical bars (BarBox) have some keyboard shortcuts. LFO Wave on Main tab and Gain, Width, Pitch, Phase on Wavetable tab are using BarBox. Shortcuts are enabled after left clicking BarBox and mouse cursor is on the inside of BarBox. Cheat sheet is available on Infomation tab.

Input Control
Left Drag Change Value
Shift + Left Drag Change Value (Snapped)
Ctrl + Left Drag Reset to Default
Ctrl + Shift + Left Drag Change Value (Skip Between Frames)
Right Drag Draw Line
Shift + Right Drag Edit One Bar
Ctrl + Right Drag Reset to Default
Ctrl + Shift + Right Drag Toggle Lock
a Alternate Sign
d Reset Everything to Default
D Toggle Min/Mid/Max
e Emphasize Low
E Emphasize High
f Low-pass Filter
F High-pass Filter
i Invert Value (Preserve minimum)
I Invert Value (Minimum to 0)
l Toggle Lock under Mouse Cursor
L Toggle Lock for All
n Normalize (Preserve minimum)
N Normalize (Minimum to 0)
p Permute
r Randomize
R Sparse Randomize
s Sort Descending Order
S Sort Ascending Order
t Subtle Randomize (Random walk)
T Subtle Randomize (Converge to 0)
z Undo
Z Redo
, (Comma) Rotate Back
. (Period) Rotate Forward
1 Decrease
2-9 Decrease 2n-9n

Snapping is not available for all BarBox. If you’d like to have snapping for certain BarBox, feel free to open issue to GitHub repository.

Edit One Bar with Shift + Right Drag holds a bar under the cursor when mouse right button is pressed. Then only changes that one bar while holding down mouse right button.

Toggle Lock with Ctrl + Shift + Right Drag behaves as line edit. When right mouse button (RMB) is pressed, it holds the opposite state of the bar below mouse cursor, then use the state for the rest of bars. For example, if RMB is pressed on a locked bar, dragging unlocks bars while holding down RMB.

Some BarBox has scroll bar to zoom in. Scroll bar has handles on left end and right end. To control zoom, use Left Drag on one of the handle. Scroll bar also has following controls:

Caution

Pressing Refresh LFO or Refresh Table button stop sound. They also stop all midi notes.

Wavetable Specification

128 wavetables are generated. The number 128 comes from MIDI note number range. The indices of wavetables correspond to MIDI note numbers.

When tuning is not exact, an index will be truncated to semitones. For example, if MIDI note number is 60 and tuning is -20 cents, index becomes floor(60 - 0.20) = 59. Thus, 59th wavetable will be used.

Block Diagram

If the image is small, use Ctrl + Mouse Wheel or “View Image” on right click menu to scale.

Diagram only shows overview. It’s not exact implementation.

Parameters

Main Tab

Gain

A, D, S, R

Gain envelope parameters.

Gain

Master output gain.

Lowpass

Naive 3-pole low-pass filter.

Cutoff

Cutoff frequency of the filter.

Resonance

Resonance of the filter. Be careful when turning to right, output will be loud.

KeyFollow

When set to right-most, cutoff frequency is set to the frequency of a note. When set to left-most, it only use the value of Cutoff.

A, D, S, R, Amount

Filter envelope parameters. Amount changes the amount of modulation to cutoff.

Tuning

Octave, Semi, Milli

Changes master pitch.

Milli is 1/1000 of semitone or 1/10 cent.

ET, A4 [Hz]

Changes tuning.

ET stands for equal temperament. Note that when ET is less than 12, some notes becomes silent due to frequency becomes too high or too low.

A4 [Hz] is frequency of note A4.

Unison

nUnison

Number of voices used by unison.

To avoid interruption of release, increase the number of nVoice in Misc. section. Note that increasing nVoice consumes more resources.

Detune, Random Detune

Detune is the difference of pitch between voices used in a unison.

When Random Detune is checked, amount of detune changes for each note-on.

random = RandomDetune ? rand() : 1
detune = pitch * (1 + random * unisonIndex * Detune)
GainRnd

Amount of randomization of gain for voices used in a unison.

Phase

Amount of randomization of phase for voices used in a unison.

This parameter makes no effect when Reset in Phase section is checked.

Spread, Spread Type

Spread is an amount of stereo spread for a unison.

Spread Type provides options to assign panpot values according to voice pitch.

Phase

Phase

Initial phase of oscillator.

Reset

When checked, resets oscillator phase to the value set by Phase.

Random

When checked, randomize phase for each note-on. In this case, value of Phase becomes range of randomization.

Misc.

Smooth

Time length to change some parameter value to current one. Unit is in second.

List of parameters related to Smooth. * represents wild card.

Poly

Maximum polyphony. Lowering the number of this option reduces CPU load.

Seed

Random seed. This value change random number sequence.

LightPadSynth has 2 random number generaters. One is used in Main tab and the other is in Wavetable tab.

Delay

Mix

Mixing ratio of filter output and delay output.

Feedback

Feedback of a delay. Positive feedback when turning right. Negative feedback when turning left.

Attack

Attack time of gate between filter output and delay.

Semi, Milli

Delay time relative to note frequency. Following equation is used.

delayTime = 1 / (noteFreq * pow(2, (semi + 0.001 * milli) / 12))

LFO

Tempo, Multiply

Sets LFO frequency according to current tempo. Lower numeral represents the length of note. Upper numeral is the number of notes.

Value of Multiply is multiplied to the frequency calculated from Tempo.

// (60 seconds) * (4 beat) = 240
lfoFrequency = Multiply * (BPM / 240) / (TempoUpperNumeral / TempoLowerNumeral)
Amount

LFO frequency modulation amount.

Lowpass

Changes cutoff freequency of low-pass filter for LFO.

Interpolation

Type of LFO wavetable interpolation.

Refresh LFO

Refresh LFO wavetable based on current value of LFO Wave.

Note that refreshing wavetable stops sound. It also interrupts MIDI notes.

LFO Wave

LFO waveform.

Wavetable Tab

Overtone Controls

Gain

Gain of profile.

Width

Width of profile.

Pitch

This value is multiplied to profile center frequency.

Phase

Range of randomization for the phase of profile.

Pitch

Base Freq.

Fundamental frequency of wavetable. Note that if this value is small, master pitch becomes out of tune.

Multiply, Modulo

Changes profile center frequency.

profileCenterFrequency = mod(
  BaseFreq * profileIndex * overtonePitch * Multiply,
  440 * pow(2, (Modulo - 69) / 12)
)

Spectrum

Expand

Scaling factor to shrink/expand the spectrum along to frequency axis.

Shift

Shift spectrum along to frequency axis.

Comb

When this value is higher than 1, it changes the shape of profile like a comb. The value specifies interval between peaks.

Shape

Changes profile shapes by using the value of Shape as an exponent.

shapedProfile = powf(profile, shape);

Phase

UniformPhase

When checked, phase of a profile becomes an uniform value.

Random

Seed

Random seed. This value change random number sequence.

LightPadSynth has 2 random number generaters. One is used in Main tab and the other is in Wavetable tab.

BufferSize

Size of a wavetable. The power of 2 values can be selected from 2^10 to 2^21.

The value inside parentheses indicates number of bytes in a sum of all wavetables. A number of bytes is calculated with following equation.

bytes = 4 * 128 * BufferSize

Modifier

Gain^

Exponent for Gain in overtone control.

profileGain = pow(Gain, Gain^)
Width*

Multiplier for Width in overtone control.

profileWidth = Width * (Width*)

Refresh Table

Refresh PADsynth wavetable based on current configuration of Wavetable tab.

Note that refreshing wavetable stops sound. It also interrupts MIDI notes.

Change Log

Old Versions

License

LightPadSynth is licensed under GPLv3. Complete licenses are linked below.

If the link above doesn’t work, please send email to ryukau@gmail.com.

About VST

VST is a trademark of Steinberg Media Technologies GmbH, registered in Europe and other countries.