Hi Xavier, it is the standalone. Tried on Mac Os X and it happens in Mavericks, Yosemite, El Capitan and Sierra. MacPro and Macbook air.
USB conection only and no
Steps.
While editing any patch (loaded from DX7 or internal preset) sysex try to push the patch to the Preen and patch becomes corrupted. Often by re-pushing solves it or make it worse. It is random. Other times it completely corrupts the patch and is irrecoverable rendering work unusable. I sounds like it alters the FM levels, envelopes possibly and modulation index. FM frequency ratios seem to be maintained ok.
I have noticed that if you are playing a midi keyboard or if there is a midi sequence coming in to the FM2 (to test the patch edit), the corruption can be worse. Sometimes by stopping the midi note and waiting for it to die away and then pushing again can resolve it. Maybe some weird MIDI loop going on?
thank you very much.