[synth-diy]Where to look for VCO sound samples?

[Martin Czech]

I guess you'll have to interpolate the table for most frequencys.

Won't this alter the sound?  If so, is it of great use to use an 
cumbersome made original sample?

Never the less, a compilation of pure vco sounds would be very
interesting, do they really sound so different? In most cases it is
not possible to obtain pure vco sounds however, since there is no jack,
one has to tap it, but where? vcf and vca wide open is vcf and vca wide
open is and not vco direct out.

And the next question that comes to my mind is that the effects of noise,
epsecially 1/f noise in expo converters and power supply (soft) sync
were dicussed here, and I guess they have also an influence on sound
(beating).  Now, a table can never do that.

I believe that the key to analog vco sound is that it is no
stationary wave, each cycle looks slightly different and
the "phase error" adds up a lot over time.

At least the analog osc I have build do so.

This was the destructive part ;->

Maybe, if the investigations go on like this there may be some
respectable theory on the sound of certain synth` vcos, if e.g. one
could find out that phase noise (1/f) was a contribution to
some vco, one could think of mimiking this via table pointer
modulation, or interpolation modulation, if you like.

So far, we have the following reasons mentioned for sound differences:

-nonideal waveform (ie. flat top, slow discharge)
 you would need a multisample or better a mathematical model for all
 frequencys
-phase noise and jitter 
 perhaps start with a good interpolator, then add noise to the phase,
 try filtered noise and so on, until the digital version shows
 some detail of analog sound (heard beating against a crystal osc. eg.) in 
 a very exagerated fashion
-sync was reported from various osc cores
 some kind of sensitive window in which a sync may happen
 
 
m.c.


:::From: mikko.a.helin at nokia.com
:::To: synth-diy at node12b53.a2000.nl
:::Subject: [synth-diy]Where to look for VCO sound samples?
:::Date: Mon, 23 Oct 2000 13:30:02 +0300
:::
:::Hi,
:::
:::I'm writing a VST instrument plugin and I have an idea to try virtualize
:::some famous VCO designs (Moog, TB-303 etc.). Does anyone have a link to site
:::with samples of pure VCO's?
:::
:::BR,
:::Mikko Helin