I'm trying to figure out why some samples in Dimension Pro will sustain indefinitely while others will sustain for a number of seconds then cut out. For example, the Ahh Female program sustains forever (if I hold the key or step on my sustain pedal) but the Ahh Male Choir and the Boy's Choir go on for about 8 or 9 seconds then stop, even while I hold the key. Playing with the modulator's sustain point doesn't have any noticeable effect (the boys's choir doesn't use the modulator section).

It all starts with the samples, the female sample loops, the male sample does not. If I were guessing why, they were trying to mimic a Mellotron with the Aah Male Choir patch.

Use the "S" to add a sustain to the amp envelope.  If that doesn't work you may have to add sustain to the SFZ file or add it in the raw sample.

There is an old thread about this in the instrument forum.

Why?  Either the mellotron theory by scook or maybe because males take breaths.  Obviously, some one thought that females don't and can go on and on.  It only seems that way, at times.

:-)

Thanks for the replies.  I've learned a lot in the last hour or two.  I read up on the SFZ file format, then opened up the three .spz files corresponding to my examples.  None of them have loops defined in the .spz file.  However, I added a loop to the boys choir and (hurray !) it loops on the interval I specified.  I just picked random start and end points so the looping didn't sound too great but I can play with that.
 
I also just discovered that a .wav file can have a loop defined in it ?  I guess that's where the females hide their loop.  I have to look into that.
 
I don't think there's a Dimension Pro manual and the program's help files don't go very deep.  I think I found the thread you mention AT in the instruments forum and it points to the book "Cakewalk Synthesizers: From Presets to Power User" by Simon Cann.  I'll have to get myself a copy since I have X1 Production Suite that has a bunch of sythesizers that I want to learn how to use.
 
My singers don't have to breathe .  I'm playing around with using several choirs in the same way you'd use constant strings.
 

It is a good book. There is even a free pdf update for z3ta+2 at Simon's website.

About the loop being in the audio file...
 
First of all they're sets of .flac files, not .wav's.  Then, for some reason I can't import the female ones into an audio track to be able to look at them, I get the DirectShow error, but I can import other .flac files of some of the other DimPro samples, including the men's choir.
 
This will need further study, but it's late...
 
And I guess I'll continue this over in the instrument forum.  I'm still getting used to the forums here and had sort of forgotten about it.
 

You might want to check out this thread http://forum.cakewalk.com/fb.ashx?m=1410821 The samples are wav files so they may be easier to work with. In addition to the combined choir there are a bunch of other Mellotron samples with prebuild sfz files.

Thanks scook !