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: 1 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
> >
> >
> >