Parallel World 0.15

15 Aug 2021 | Source | Translator: KLAD and Venkanto

Tags: , , ,

VST plugin for synthesizing vocals with UTAU in your DAW, with real-time rendering.

Download the plugin from the source link above. After unzipping, the folder includes three documents (readme.txt, pwmanual.pdf, history.txt) that are translated below. You may also opt to download the engine test tool. Please continue reading for instructions on how to install and use Parallel World and the engine test tool.

Download page screenshot

Read Me

Name: Parallel World (placeholder name)
Version: 0.15
Release Date: 2021/08/13
Type: Free software
System Requirements: Windows 10/8.1
Developer: Ackie
Contact: [email protected]


Parallel World is a VST plugin that allows you to use UTAU voicebanks inside your DAW.
Changes to the .ust file are reflected in the sound output in real time.

How to use

Please refer to the PW Manual below.

The copyright of this software belongs to the developer, Ackie.
The developer is not responsible for any damages incurred during use of this software.


Please notify me via e-mail me of any comments, questions, concerns, or bug reports.

Email: [email protected]
Ackie Sound:
Support forum:

Parallel World (placeholder name) Manual [Ver. 0.15]


Download English Manual


Parallel World is a VST® plugin that allows you to use UTAU voicebanks inside your DAW. Changes to the .ust file are reflected in the sound output in real time.


Put ParallelWorld.vst3 in the VST plugin folder.
Note: This is a 64 bit VST3 plugin.


How To Use

  1. Run pwsettings.exe, set the “voice” folder path and the UST file path, then press the Save button.
    Note: In the current version, the UST file path and voicebank folder path cannot use environment-dependent characters.
    pwsettings screenshot, set paths
  2. Create the WAV file that will serve as input to the VST plugin. Set the length in seconds to be longer than the UST, then press the Create button to save the WAV file.
    Note: The WAV file includes a special noise. Parallel World reads this noise and replaces it with UTAU vocals.
    Note: If the WAV file is shorter than the UST, there will be no audio output past the end of the WAV file.
    pwsettings screenshot, create file
  3. In your DAW, import the WAV file created in Step 2, and add ParallelWorld.vst3 to that track. The plugin will synthesize vocals using the UST file corresponding to the channel selected in the settings window.
    Note: This plugin runs as a VST effect.
    Note: An alarm sound will play until frequency files are finished generating.

Limitations & Other Things to Keep in Mind

Special Features

Flags specific to Parallel World are W (growl, 0-100, default 0), S (devoicing, 0-100, default 0), and R (morphing, 0-100, default 0).


This plugin can use a main voicebank and morphing voicebank together to synthesize a vocal tone between the two.
The R flag specifies the ratio between the vocal tones. When R is 0, it’s the main voicebank only, and when it’s 100, it’s the morphing voicebank only.

The text added to the lyrics when using the main or morphing voicebank should be specified in a command in the project name. The plugin will automatically add this text to the lyrics, so there’s no need to add it to the notes themselves.

Situation Command
Main voicebank prefix v1p"text"
Main voicebank suffix v1s"text"
Morphing voicebank prefix v2p"text"
Morphing voicebank suffix v2s"text"

Example settings: For the morphing voicebank, “S” is used as a suffix to specify the expression.
UTAU project properties screenshot


Problem Cause and Solution
No sound Make sure to add the WAV file from pwsettings.exe to the track.
CVVC voicebanks are not supported.
Sound gets cut off Multiple tracks cannot use the same channel. Make sure to change channels if you want to use multiple at once.
Check the buffer size in your DAW settings.
Flags have no effect Only BRE, g, t, W, S, and R are supported.
Pitch is incorrect Save the UST file using UTAU ver 0.4.x or compatible software.
You need to set the pitch mode in Project > Project Property > Rendering Options. Use M1 for Mode 1 and M2 for Mode 2.
Single beep alarm Multiple tracks cannot use the same channel. Make sure to change channels if you want to use multiple at once.
Still generating frequency files. Please wait for it to finish.
Double beep alarm Check to make sure the UST file exists.
If the UST file path or file name has special characters, remove those.
If the UST was saved in UTF-8, resave it as the default encoding.
Triple beep alarm Check to make sure the voicebank folder exists.
Check pwsettings.exe and make sure the voice folder path was written correctly.
If the voicebank is in somewhere like Program Files, move it to another folder where admin permission is not required.
If the folder path or file name has special characters, they cannot be used.
If the oto.ini was saved in UTF-8, it cannot be used.

Engine Test Tool

This tool is for testing the function of the engine without using a DAW.
Set the UST file path and press the “再生” button to start playing. To play it again, wait for a moment after pressing “停止” and then press “再生”.

engine test tool screenshot

Update History

ver. 0.15 2021/08/13

Fixed crash when full width characters are used in flags.
Improved behavior when using invalid voicebank settings.
Increased the maximum number of characters in lyrics.
Enhanced error checks.

ver. 0.14 2021/08/12

Fixed crash when an invalid voicebank is specified.
Support for drag and drop of UST files into settings.

ver 0.13 2021/08/11

Fixed bug where oto.ini wasn’t read correctly when alias isn’t specified.

ver. 0.12 2021/08/11

Support for expressive voicebank morphing.
Fixed crash when nonexistent alias was used. Fixed bug where specific notes used together would cause memory usage to continue increasing during playback.
Improved overlap processing.

ver. 0.11 2021/08/06

Created general public release version.

ver. 0.10 2021/08/01

Support for switching between Mode1 and Mode 2 in playback options.

ver. 0.09 2021/08/01

Fixed bug that made voice libraries in non-default folders unusable

ver. 0.08 2021/08/01

Mode 2 support.
The lowest point in the pitchbend determines which pitch in the prefix map is used.
Added error logging.

ver. 0.07 2021/07/31

Multiple channels are now supported.

ver. 0.06 2021/07/27

Tempo changes support. Fixed bug where Rendering Options in the project settings were not applied.

ver. 0.05 2021/07/24

The t flag support.
Fixed bug where BRE wasn’t applied normally.
W flag (growl) and S flag (devoicing) have been added.

ver. 0.04 2021/07/24

BRE and g flag support.
An error now occurs when a voicebank folder is under Program Files.
A feature was added to indicate errors by playing a sound.

ver. 0.03 2021/07/23

A tool has been created to check the function of the engine without using a DAW.
Real time reflection of changing voicebank is now supported.

ver. 0.02 2021/07/22

Fixed bug where there was no audio output when the voicebank folder was outside of %VOICE% or %DATA%.

ver. 0.01 2021/07/22

Initial release.