YAMAHA YMU759 FAQ:
Q: There is no information anywhere about MMF, how do you managed to develop a tracker for this closed format?.
A: Many months of reverse engineering.
Q: I loaded some wav files on the PCM channel, but I hear the samples very fast or very slow, for what?.
A: Try to change the HZ in the PCM Channel editor, and remember that you need to export the .wav file at 8000hz/4000hz, be careful because some applications claims to do that, but, actually, they do not.
Q: I am trying to import a wav at 8000hz/4000hz with 16bits, but DefleMask does note load the sample, what is wrong?.
A: The wav file must be uncompressed, some apps compress the wav file without warning (for example, Windows Sound Recorder), so you need to use another app.