Patches and discussion for Ensoniq VFX family

Hi again Suzanne,
I get the idea that the techknology for sample playback and pitch
shifting is diferent.  I get the idea that in sample playback, you are
essentialy varying  the speed of a recording.  Resolution is lost when
you slow down a digital recording.  In speeding up I imagine there is
some kind of sample rate truncation going on.  With pitch shifting, like
you said, waves are being added and subtracted, no doubt stretched and
compressed too.  When I bent the sounds down, it sounded like a lowpass
filter with a drastic rolloff was added.  I don't think that the high
notes actualy disapeared.though they got more an more like sine waves as
you went up. Hgh notes got softer but that might be typical when a sound
looses harmonic content.
I wonder which technology the VFX uses on it's pitch bender.  They might
have multi sampled a sawtooth wave to make it less bright in the upper
reaches of the keyboard, thus avoiding noise form upper harmonics
interacting with the sampling rate.  That could explain the distortion I
got when I bent notes upward.  The sound was a lot brighter.  Like I
said, the distortion might not have sounded bad to me.  So the changes
could be due to different waves or to some wave shaping idiosyncrasies of
a pitch shifter.

I'm including the patch.  I hope the patch makes it.  I'ts a uuencoded
.zip. You will need to rename so that it has a .uue extension.  If you
are using windows 95, you can load it with notepad and use the "save as"
option.  

Here are some detailes about the patch:

This tiWith no patch buttons you get a sound where the pitch is bent
down.  With the left patch button you get a sound from bending the patch
up two octaves.  Right button: both.  Both buttons: a detuned layer.  It
looks like the patch already uses the variantion that I mentioned in the
email.  
 
Remember to puch the Mod wheel all the way forward.  Pull it all the way
back to hear the original sound.  You can compare the two by pulling back
on the wheel and playing an octave down.




I hope this is useful.
Nathan