B00 File

What are B00 files and how to open them

Are you having problems opening a B00 file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your B00 files.

What is a B00 file?

A .B00 file is an Electone Registrations file.

Electone Registrations files hold saved settings used by Yamaha Electone instruments. They store user-defined combination settings known as Registrations, which include presets for voices (sound selections for each keyboard or pedal), rhythm beats, rhythm sequences, possibly registered shifts (assignments that change during playback). These files are created when using Electone's MDR ("Music Data Recorder") or related functionality to record or back-up performance song data alongside these settings. Registration data in these files defines how the instrument sounds and responds for a given song.

Such files are written by the Electone itself when saving a Song via MDR or when exporting a Song to external media (like USB flash drive, SmartMedia, etc.). A Song consists of multiple components: one MIDI-format file recording the actual performance keystrokes, one Registration data file with voice/rhythm/sequence settings, and sometimes additional files for converted XG data, along with folder management files. When restoring or loading the Song, the Electone reads the Registration file to re-establish its sound-setting state.

Files in this format begin with a specific signature: the ASCII sequence ".Cpx" (hex F0 43 70 78 00) at offset 0.

How to open B00 files

Important: Different programs may use files with the B00 file extension for different purposes, so unless you are sure which format your B00 file is, you may need to try a few different programs.

While we have not verified the app ourselves yet, our users have suggested a single B00 opener which you will find listed below.

Last updated: August 22, 2026

Various apps that use files with this extension

These apps are known to open certain types of B00 files. Remember, different programs may use B00 files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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