The sysex handling is completelly disaster, it handles the first few bytes correctly, after that it starts loosing data bytes, usually all bytes. The firmware has more problems: the midi running status is not handled on the input side, stange 'note on' messages are inserted in the case of receiving running status for any controller. It has usually no optocoupler on the MIDI input which makes it incompatible with some devices. The original converter has some design flaws. This is a replacement board for the cheap chineese USB to MIDI converter for fixing all issues with the cheap electronics.
