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@... >
>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
>
>
>