[sdiy] MOTM-800 clicks. Arg!

[Ian Fritz]

This is a problem I worked on many years ago.  The concern is that the 
*slope* discontinuity produced by the usual attack generator can cause a 
pop, even though the total attack time is not all that short.  I built a 
circuit that rounded off the the beginning of the attack curve and was able 
to convince myself that the attack sounded more natural and that shorter 
attack times could be used without getting pops.  Unfortunately, I don't 
remember how I did the circuitry and I can't find any documentation.  As I 
remember it was a bit complicated.  Anyway, the usual attack curve (step 
voltage driving RC) seems unnatural.

   Ian



At 05:54 AM 10/16/2003, Czech Martin wrote:
>Depends on your expectation.
>
>I mean, you try to instantly switch on a non synchronized VCO
>wave, this will cause sudden jumps in the signal, according
>to VCO and Envelope timing. Sometimes you hit the VCO near 0,
>sometimes near maximum level. Gives a "random" click
>pattern.
>
>Remedy: ensure via synchronisation that
>the VCO starts at zero when the fast envelope does the transient
>start. So the clicks should be much less audible (well,
>VCA feedthrough will stay, of course).
>Or: ensure that the VCO will be hit always at maximum.
>Much less anoying then a "random" behaviour.
>
>A good reason for having a tuneable sync, i.e. the
>phase during sync will settle to some adjustable
>value. Have seen this for LFO, but not for VCO circuits.
>
>
>Another question: we could ask what kind of thing this VCO-VCA-Env
>thing is modelling. If you create sound by applying a impulse to
>a 2nd order resonator, you will see that the rise time depends
>on frequency and resonance. Perhaps a very simple ideophon
>model. It will never happen that the wave starts at 100%, the
>differential equation will always start with 0 (given the initial
>conditions say so). I've just done this for a composition
>I'm going to present this Saturday or Sunday.
>
>The usual synth circuits divide the action
>of a resonator in two parts, frequency and time transient,
>which are not correlated. Thus it is not surprising that things
>do not work as supposed (in the sense of said modelling).
>
>I have heard this fast attack problem on many synths, also digital.
>I guess all such configurations show the same behaviour, if the
>envelope is really fast enough.
>
>m.c.
>
> > -----Original Message-----
> > From: owner-synth-diy at dropmix.xs4all.nl
> > [mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of Aaron Day
> > Sent: Donnerstag, 16. Oktober 2003 13:30
> > To: synth-diy at dropmix.xs4all.nl
> > Subject: [sdiy] MOTM-800 clicks. Arg!
> >
> >
> > Hey all.
> >
> > Anybody out there having success at making their MOTM-800 envelopes
> > click free for short enevelope settings? I'm about at my wits
> > end here
> > maybe someone can make a suggestion. I'm on a project where I
> > need this
> > kind of sound and would like to use the modular before I
> > resort to the
> > sh-101.
> >
> > Quick background.
> >
> > When I I have attack at 0 and a short decay setting I always get a
> > click when the EG is driving a VCA when I back off the attack to the
> > point that I lose the click I have a mushy attack. I want to
> > get a nice
> > healthy "knock" out of my EGs so that I can sculpt kick drums etc...
> >
> > I'm gating/triggering the EGs from my ACS TM-116 sequencers
> > which work
> > fine--if it weren't for the click.
> >
> > I have two carefully built EGs so I'm counting against some kind of
> > build error.
> >
> > Tips hacks suggestions?
> >
> > TIA,
> >
> > ad
> >
> > ________________________
> > Aaron Day
> > Marienburgerstr. 33
> > VH EG rechts
> > 10405 Berlin
> > Germany
> >
> > Mobile +49 179.750.1854
> > Office +49 (0)30.255.627.94
> > Fax +49 (0)30.255.627.96
> > ________________________
> >
> >