Doepfer

hello zoran,

just some additional info about the a109 vca.
the a109 vca has a combined response curve, you can
also find this information in the a109 user manual.
from 0 to +200 mv the response curve is exponential
(+200 mv is approximately -20 db). from +200 mv to +5 v
the response is linear, +5 v is 0 db or unity gain.

best wishes

ingo



--- In Doepfer_a100@yahoogroups.com, "Zoran Bosnjak" <dj_allin@h...> 
wrote:
> 
> Thanks for the excellent response Ingo. Everybody reading this 
post, please 
> notice that after all, it is only my perception that by bypassing 
VCA 
> entirely in my bass patch, the A-109 filter got its character 
improved by 
> getting slighly smoother, almost liquidy quality. Almost like VCA 
was 
> holding it back - now its more even (smooth). When I am saying more 
even, 
> imagine curve of the sound as being curved (obvious), but no dents 
in the 
> line. With VCA, it is almost like curve is dented, uneven, with 
slight 
> changes in volume. I did the test by opening the AMP knob on A-109 
> completely. I could even hear slight noise (but negligible, and 
remember 
> that's with AMP knob open full, and no envelope applied).
> What manfacturers do with their chip/filter application is still 
mystery to 
> me. This is my third encounter with the same chip - I also have 
Microwave I, 
> and I used to own Waldorf pole filter (forgot the name, that small 
orange 
> thing). And that Waldorf standalone filter unit sounded 
unbelievable 
> (smoothness and acid of 303 if needed, but with different, almost 
Moog 
> character. Almost like subtle reverb was applied to it). I sold it 
because 
> it was slow to edit, due to its menu system, and guess what: it was 
sticking 
> out too much in the mix (beauty is curse sometimes :-) But this 
Waldorf 
> experience made me buy A-109, and I KNEW there was that beautifull 
character 
> hidden somewhere (behind VCA :-)
> 
> But your post is eye-opening Ingo. I will look for other 
implementations 
> where A-109 VCA can contribute to character, and not take away. And 
it's 
> just unbelievable how little detail can contribute lot to sound,
> 
> Regards,
> 
> Zoran
> 
> 
> 
> >From: "selfoscillate" <synaptic_music@y...>
> >Reply-To: Doepfer_a100@yahoogroups.com
> >To: Doepfer_a100@yahoogroups.com
> >Subject: [Doepfer_a100] Re: A-109 Improvement
> >Date: Wed, 06 Apr 2005 13:47:53 -0000
> >
> >
> >
> >hello zoran,
> >
> >well, i don't think that the vca is low quality,
> >it just has a different response curve. the vca-part
> >of the a109 has a clear sound with low distortion
> >and low noise, so it can't be named low quality.
> >low quality usually means that the vca is noisy.
> >the response curve of the a109 vca is partly linear
> >and partly exponential, depending on the amount
> >of voltage applied to the vca circuit via the cv inputs
> >and/or the gain pot. this is a somewhat different behaviour
> >than on the other vca's and probably what you don't like,
> >especially when you use an envelope or lfo to open the vca,
> >instead of using a fixed voltage.
> >
> >also it seems to be a question of personal taste.
> >some like the cem-based vca's, others prefer the ca3080-based
> >or even the vactrol-based vca's, which have a completely
> >different response curve. my opinion is that each type
> >of vca has it's advantages, you just have to find the
> >right application for it.
> >
> >best wishes
> >
> >ingo
> >
> >
> >
> >
> >--- In Doepfer_a100@yahoogroups.com, "Zoran Bosnjak" 
<dj_allin@h...>
> >wrote:
> > > Hello,
> > >
> > > I read so many posts about A-109 that were saying "this module 
is
> >good for
> > > starters, you get decent filter, VCA, and panner." Well, this is
> >what I
> > > found out: this filter sounds better when used without VCA that 
is
> >the part
> > > of the same module. Without VCA on A-109, the filter becomes 
very
> >smooth -
> > > it is a small difference, but possible to hear. And because of 
that
> > > smoothness, suddenly this filter has a strength/beauty in a mix
> >that was not
> > > present before.
> > >
> > > I was just patching some bass sounds (VCO, A-109 filer, and
> >envelope), and
> > > comparing them with ARP Axxe that I own as well. What I like 
about
> >A-109
> > > filter is a sweet tone, mellow Curtis with very tiny hint of 
Moog.
> >Still
> > > sounding harder than super smooth and round ARP Axxe (mine has 
4075
> >filter,
> > > one that got replicated in Modcan line of modules).
> > >
> > > So, two conclusions: A-109 filter is more than "just decent", 
it's
> >actually
> > > very good. And by getting the module, you are getting low 
quality
> >VCA, that
> > > can impact your sound (well, you can always find CV duty for 
VCA on
> >your
> > > system). I would love to hear if somebody has experience similar
> >(or
> > > completely different, of course) to mine.
> > >
> > > Regards,
> > >
> > > Zoran
> >
> >
> >