Euphoria features stellar voice acting from top-tier seiyuu. The repack comes pre-configured to run the Japanese voice patch without sync issues. Hearing the raw emotion during the infamous "true route" is an essential part of the experience.
The original Japanese release (2011) was notorious for technical quirks. The 2016 "Repack" for the English version addresses: euphoria english version repack
Bottom line: if you’re playing Euphoria in English today, this is the only version worth using. Euphoria features stellar voice acting from top-tier seiyuu
For the audio hobbyists reading this, you might want to attempt making your own high-fidelity repack. Here is the simplified workflow used by top fan editors: Bottom line: if you’re playing Euphoria in English
If you are uncomfortable with repacks, consider: