Three options come to mind:

1) Get an analog keyboard! It's time.
2) The analogue systems RS50 has a trigger generator.
3) Using stuff you already have option: Use an LFO with extremely low
range and PWM and sync. For PWM maybe you'll need a comparator. Turn
the range to the bottom, the PWM to the smallest spike, and use sync
to create a trigger.

Option 1 is clearly the best.

Monroe

On Jan 10, 2009, at 4:06 PM, madrayken wrote:

> Apologies - I think there's been a misunderstanding.
>
> I'm trying to achieve the 'wooden block' sound as popularised by
> Buchla synths.
>
> 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.
> 2) sending a signal straight from the midi-cv gate to the filter. The
> problem here is that a signal is generated both on a press and release
> of a key. As far as I am aware, this is because a gate represents a
> shift from positive to negative, OR the reverse.
>
> What I want is a 'trigger' - a very short square wave which occurs
> only on key press.
>
> Is that clearer I do *not* need two triggers!
>
> --- In Doepfer_a100@yahoogroups.com , Florian Anwander <fanwander@...>
> wrote:
> >
> > Hi madrayken
> >
> > > In trying to pursue this Buchla-style experiment, I've found it
> almost
> > > impossible to derive a decent audio-trigger from an ADSR
> envelope, no
> > > matter how fast.
> > I am not sure what you are asking for. What do you mean with
> > "audio-trigger" A trigger signal generated as soon as the level of
> > some audio signal is higher than a certain threshold (thats what I
> would
> > understand) Or do you mean an spike like the "klick"-sound from a
> drumpad
> >
> >
> > > Gates work nicely, but you're forced to have two
> > > events: one on key-press and one on release.
> > This sentence i don't understand.
> >
> > > I've got plenty of ADSRs, VCAs, Comparators and other things,
> and have
> > > tried using the voltage comparator to create a gate from an ADSR
> > > (close but no cigar). Can anyone suggest a way of generating a
> trigger
> > I think you have a wrong understanding of the word "trigger".
> > - A trigger defines a point on the time axis and is usually
> technically
> > achieved by a transition between two defined voltages. It defines
> the
> > moment when a event starts to happen.
> > - A gate defines the duration of an event and starting point of this
> > event. You may describe a gate as two triggers: one positive
> transition
> > at the start of the gate and one negative transition at the end of
> the gate.
> >
> > Taking this definition is respect, I am asking: for what patch
> exactly
> > do you need two triggers Knowing your answer to this question I
> might
> > give you a more profound help.
> >
> > Florian
> >
>
>
>



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