Wavtool4vcv

Cause: You are using a VCV voicebank with corrupted OTO (e.g., negative Preutterance values). Fix: Open the voicebank in OTO.ini editor. Ensure Preutterance (the number before the comma) is always greater than 0.

Why should you switch? Let’s compare the two.

| Feature | Classic Wavtool | Wavtool4vcv | | :--- | :--- | :--- | | VCV Crossfade Logic | Standard; often creates clicks. | Advanced algorithm designed for vowel-to-vowel linking. | | Envelope Handling | Treats all notes uniformly. | Dynamically adjusts preutterance and overlap for VCV. | | Performance Speed | Moderate. | Highly optimized; renders VCV sequences faster. | | Memory Usage | Standard. | Lower overhead for large VCV banks (like 7-voice or triphonic). | | Compatibility | All voicebank types. | Specialized for VCV (can render CV, but VCV is the focus). |

The Verdict: If you use a monopitch VCV, multipitch VCV, or CVVC voicebank, Wavtool4vcv will objectively produce cleaner exports than the original Wavtool.

ffmpeg -i in.wav -ar 44100 -ac 1 -sample_fmt s32 -af "volume=-0.1dB" out.wav

(Adjust sample_fmt to s16 for 16-bit or s32 for 24-bit-capable containers; use sox for precise 24-bit output if needed.) wavtool4vcv

Now, whenever you render a project that uses a VCV voicebank, UTAU will call wavtool4vcv instead of the default tool.

Unlike modern VST plugins, Wavtool4vcv is a legacy executable file. Here is how to set it up on Windows (the primary OS for UTAU).

Step 1: Locate the Download Because the original distribution sites have shifted, the safest place is the UTAU Toolkit archive or the official UTAU forum mirrored sites. Look for a file named wavtool4vcv.exe. (Avoid fake "download manager" sites; stick to community hubs like UtaForum.net).

Step 2: Backup Your Original Wavtool Navigate to your UTAU installation folder (e.g., C:\Program Files\UTAU). Find the original wavtool.exe and rename it to wavtool_original.exe. Do not delete it; some CV banks actually render better with the classic tool. Cause: You are using a VCV voicebank with corrupted OTO (e

Step 3: Install the New Tool Copy wavtool4vcv.exe into the UTAU folder. Rename this copy to wavtool.exe. UTAU will automatically call this file when rendering.

Step 4: Configure Your Voicebank Properties Wavtool4vcv works best when your VCV voicebank has proper OTO.ini settings. Ensure the Preutterance and Overlap fields in the OTO are mathematically logical (e.g., Preutterance should generally be between 50–250ms).

Step 5: Advanced Configuration (The wavtool4vcv.ini file) For power users: create a text file named wavtool4vcv.ini in the same folder. You can add parameters like:

When nothing is plugged into IN, Wavtool acts as a generator based on the shape drawn in the editor. ffmpeg -i in

Best for: Whispery, soft VCV banks. Why: TIPS creates subtle noise; Wavtool4vcv ensures that noise doesn't accumulate into a hiss at note boundaries.

Do NOT use: Wavtool4vcv with very old resamplers like resampler.exe (the default) because the default resampler produces phase distortion that no wavtool can fix.

wavtool4vcv is a custom “wavtool” for UTAU. In UTAU’s architecture, a wavtool is a helper program that extracts the correct portion of a .wav file based on the timing instructions in a .ust file. The default wavtool (wavtool.exe) works fine for simple CV (Consonant-Vowel) banks, but it struggles with the overlapping, crossfaded nature of VCV samples.

Developed to address these limitations, wavtool4vcv intelligently handles the unique timing requirements of VCV voicebanks, where each note contains a vowel from the previous note and a consonant-vowel pair for the current note.