I wrote the code to take the Expressionmate MIDI and convert it to CV
with the PSIM. I know the Expressionmate is a full 14 bits of
pitchbend data which is quite smooth. I translate this full 14 bits
across 0 to 10 volts in the PSIM so the increments are limited by the
12 bit resolution of the PSIM.
I designed my own module using a PAiA MIDI2CV and it does exhibit
considerable zipper effect. I haven't gone through the PAiA code but
I can only guess that they are ignoring the the lower 7 bits (second
data byte) or the DAC resolution is just too low. With the PSIM it
is
quite smooth. I also have another module that I use with the PSIM to
level shift the outputs back to 0 +/- 5 volts.
Dave
--- In motm@yahoogroups.com, ivancu@a... wrote:
> From: "djbrow54" <davebr@e...>
> >Another option is the ExpressionMate. I know it is expensive
but I
already have one. I've
> >written the code for the PSIM to adapt the MIDI to basic CV
functionality. The
> >ExpressionMate can also be used as 3 separate ribbons and it
shouldn't be too hard to
> >modify the code to support this. I'll get around to it one day.
>
> How do you get continuous smooth CV changes out of the
Expressionmate? I had one for a week and was disappointed that it
would do a glissando instead of a smooth portamento as you slid up
and
down the ribbon. Of course MIDI outputs note information so it
wasn't
surprising. But it would have been nice to have an interpolated
output that would give continuous up and down gliding over a five
octave (or more) range.
>
> Ivan