> From: Mark Pulver <mpulver@...>
>
> thebass (12:36 PM 6/14/99) wrote:
>
> >From: thebass <thebass@...>
> >
> >Not true, the Expressionist does output S-trigger and +/-
> Gates both at the
> >same time. It works like a charm.
>
> I think he's talking about short pulse (like 100ms) triggers on a NOTE_ON
> event.
>
> The Expressionist will only do step S-triggers or step voltage
> levels which
> are held in a HIGH state while the NOTE_ON event exists.
>
Yes, I was talking about a trigger pulse. The semantics get confusing
because Moog S-triggers are actually not pulses, but inverted voltage gates.
In the non-Moog world, usually a trigger signal means a pulse, and a gate
signal means a level. Anyway, the MOTM-800s need the trigger pulse AND the
gate signal to produce full ADSR unless you mod them to derive the trigger
pulse internally.
Somebody on this list (I forget who) pointed out that you CAN use the
Expressionist in an unorthodox manner with unmodified MOTM-800s to get full
ADSR response. It involves using one Expressionist gate channel set up for
positive gate, and plugging that into the GATE input of the 800, then using
a second Expressionist gate channel set up for S-Trig, and plugging that
into the 800 Trigger input. The reason this works is apparently that the
falling edge of the S-Trig is seen slightly after the rising edge of the
normal Gate voltage, and the 800 triggers from the falling edge. So it's a
happy timing situation. Of course, you burn an extra Expressionist Gate
output.
Dave Bradley
Principal Software Engineer
Engineering Animation, Inc.
daveb@...