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Update: 2022-09-09

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SevenDelay is a stereo delay with 7th order lagrange interpolated fractional delay and 7x oversampling.

The package includes following builds:

Linux build is built on Ubuntu 20.04. If you are using distribution other than Ubuntu 20.04, plugin will not likely to run. In this case, please take a look at build instruction.


Feel free to contact me on GitHub repository or

You can fund the development through Current goal is to purchase M1 mac for better macOS support. 💸💻



Place *.vst3 directory to:

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


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.


GUI Style Configuration

At first time, create color config file to:

style.json will be loaded for each time a plugin window opens.

Several color themes are available on the link below.

Below is a example of style.json.

  "fontFamily": "Tinos",
  "fontBold": true,
  "fontItalic": true,
  "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"

Font Options

Following is a list of font options.

To use custom font, place *.ttf file into custom font path: *.vst3/Contents/Resources/Fonts.

Notice: If the combination of fontFamily, fontBold, fontItalic is not exists in custom font path, default font of VSTGUI is used.

If fontFamily is set to empty string "", then "Tinos" is used as fallback. If the length is greater than 1 and the font family name doesn’t exists, default font of VSTGUI is used.

Styles other than bold, italic or bold-italic are not supported by VSTGUI. For example, “Thin”, “Light”, “Medium”, and “Black” weights cannot be used.

Color Options

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.

Following is a list of color options. If an option is missing, default color will be used.


Right Click on the controls pops up a context menu provided by DAW.

Knob and slider can do:


When the value of Smooth is near zero and change the value of Allpass Cut too fast, SevenDelay may output very loud click noise. This is caused by the filter which becomes unstable when cutoff frequency moves too fast. Recommendation is not to set Smooth parameter too low unless you have some specific purpose.

When the value of Time is set to minimum and the value of Feedback is set to maximum, SevenDelay outputs direct current (DC). To remove DC, Set DC Kill to be greater than 1.0.

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.




Delay time. Range is 0.0001 to 8.0.


Delay feedback. Range is 0.0 to 1.0.


L/R stereo offset. Range is -1.0 to 1.0.


Output volume of delayed signal. Range is 0.0 to 1.0.


Output volume of input signal. Range is 0.0 to 1.0.


Toggle tempo sync.


Toggle negative feedback. This may be useful when delay time is very short.

In/Out Spread/Pan

Panning controls. Range is 0.0 to 1.0.

In/Out Spread controls stereo spread. In/Out Pan controls stereo panning.

These parameter can be used for inverse panning, ping-pong delay etc.

signalL = inL + spread * (inR - inL)
signalR = inL + (1.0f - spread) * (inR - inL)

if (pan < 0.5f) {
  outL = (0.5f + pan) * signalL + (0.5f - pan) * signalR,
  outR = signalR * 2.0f * pan,
else {
  outL = signalL * (2.0f - 2.0f * pan)
  outR = (pan - 0.5f) * signalL + (1.5f - pan) * signalR
Allpass Cut

SFV allpass filter cutoff frequency. Range is 90.0 to 20000.0.

If Allpass Cut is 20000.0, filter will be bypassed.

Allpass Q

SFV allpass filter resonance. Range is 0.00001 to 1.0.

DC Kill

Cutoff frequency of biquad highpass filter. Range is 1.0 to 120.0.

DC Kill removes direct current from delay feedback when the value is set to be greater than 1.0.


Parameter smoothing. Range is 0.0 to 1.0. Unit is seconds.

Some parameter may produce noise when the value is changed too fast. Increasing Smooth reduces those noise.


To Time

LFO modulation amount to delay time. Range is 0.0 to 1.0.

To Allpass

LFO modulation amount to allpass cutoff frequency. Range is 0.0 to 1.0.


LFO frequency. Range is 0.01 to 100.0.


LFO waveform shape. Range is 0.01 to 10.0.

sign = 1 if (phase > π),
      -1 if (phase < π),
       0 if (phase == π)
lfo = sign * abs(sin(phase))^shape

LFO initial phase. Range is 0.0 to 2π.

LFO phase is reset to Phase for each time host starts playing.


Toggle LFO phase hold. This may be useful for live performance.

Change Log

Old Versions


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

If the link above doesn’t work, please send email to

About VST

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