By the way each mellotron sample has its own wav file for each key on the keyboard it is assigned to.
Supposedly those waves are organized in folders, where each folder would represent one instrument, you need to copy those folders from PC to CF (when in MEDIA mode on Extreme, go to Tab Utility - upper right dropping menu, select USB storage mode - then Extreme will connect with PC, you'll see it as external media on PC, do the copying).
MAKE SURE THOSE WAVES ARE IN 48 kHz, 16 bit, mono (or stereo, if you prefer) - that's maximum quality Extreme can support - if they are not, convert them before doing anything else.
When you have copied folders with wave samples, disengage USB storage mode, go to tab Load, open one folder with waves, and in upper right dropping menu choose "load selected" - do it for each wave sample. If it is really "one sample per key" you should have 61 wave in each folder.
After this, go to SAMPLING mode. You'll see MS is set to New_MS. Go to upper right dropping menu and choose Rename MS - rename it so you can manage multiple multisamples later.
Then in Samples section you see "no assign". Go to dropping arrow and choose first wave sample, it should be C2 (on 61 key Extreme). Choose this wave and in key range, just below this, choose C2 for base and top key.
Then go to the third tab, don't recall it's name right now because I don't have the keyboard in front of me, you should go to menu which will allow you to define indexes - choose indexes to cover only one key. Default option will be 12 keys, so it's hard to miss.
Return to the first tab. Now, press "Create" in the right portion of the screen. This will create next index - it should be C#2 (base and top key). Now assign wave sample C#2 to this index.
Do the same thing for each key. Next index, next sample - see how it goes?
Of course, you can stretch samples so one sample can cover up several tones, meaning original tones and few tones below and above original one, but if you have samples for each tone, leave it this way.
When you are done, loading all samples in this multisample, you should have all your keys covered.
Now, go to MEDIA mode, create a new directory (from Utility tab), then open that directory, go to tab Save, choose Save sampling data, choose option to save one multisample, choose multisample you made and save.
You should have one yourinstrument.kmp file and one yourinstrument folder (yourinstrument referring to multisample name you selected in Rename MS step).
Do the same with every other mellotron folder.
When you have several multisamples, load them one after the other - just open newly created folders and load those .kmp files.
When all multisamples are loaded, go to MEDIA mode, make new directory, go to Tab save, choose Save sampling data and then choose Saved all.
This will make one .ksc file (which will contain information about all multisamples), several .kmp files (multisamples) and exactly the same number of folders, named the same as .kmp files. This is because each multisample - .kmp stores its samples - .ksf in dedicated folders.
When you are done, go to Program mode, make a new program, or choose preset one and instead of preset multisample assign your newly created multisample or multisamples.
All the samples and multisamples arrangement can be done in Awave studio software, but if you are not familiar with ti, then it's all the same to you.
And everything I wrote is in the Parameter Guide. So read more carefully.
Regards, shrike