Hi madrayken

> I am using a resonant band-pass filter, and want to send a very short
> 'trigger' event to the filter's audio in. I have so far tried:
>
> 1) sending a short ADSR to the filter. The ADSR is not fast enough,
> resulting in a 'tonnngg' rather than a 'tok' sound.That is

Ok, this is not a fault of the trigger, but the rsonance of your
bandpass is set to high.

> What I want is a 'trigger' - a very short square wave which occurs
> only on key press.

The A162 trigger delay can produce something link this if bothe values
are set to the shortest range. Or you use an short ADSR and send it to
an comparator. This will result also in a short trigger.

But as I wrote: The extreme short ADSR causes assumingly the correct
impuls as the trigger, but your filter setting is wrong. Don't change
the trigger. Change the filter.

Florian