Doepfer

Hello Racoonboy,

Analoge envelopes are based on the loading/unloading curve of a 
capacitor, and these curves are never linear.
Our recognition and hearing is based on exponential functions in many ways:
* what we hear as a linear increase of pitch is in fact an exponential 
increase of the frequency
* what we hear as a  linear increase of loudness is in fact an 
exponential increase of the signal level
Since we have mostly linear voltage sources, the target modules 
(VCA/VCF/VCO) have exponentiator circuits at the CV input. So you can 
select whether you want exponential control or linear control (everyone 
knows this from lin and log CV-ins at the VCOs). And because there are 
typically more voltage generating modules than voltage target modules, 
it makes sense to keep the selection between lin and exp at the targets 
and not at the sources.
This is why the envelopes typically have not a selection between lin and 
exp. Adding the circuitry for lin/exp conversion at the envelope would 
increase the costs of the module immediately and significantly, because 
the converter circuit requirs manual alignment. And the work hours for 
the alignment are more expensive than the complete hardware.

Florian



Am 30.01.2015 um 08:39 schrieb Neil Kagan blinkenlicht@yahoo.com 
[Doepfer_a100]:
>
>
> It is an exponential envelope, and you can't change the curve shapes. 
> However it is very useful and if you combine it with a VCA that can be 
> switched from expo to linear then you have a very flexible setup. It 
> is also very fast for percussion sounds.
>
> Neil
>
> Sent from my iPhone
>
> On 30 Jan 2015, at 07:35, racc00nb0y@yahoo.com 
> <mailto:racc00nb0y@yahoo.com> [Doepfer_a100] 
> <Doepfer_a100@yahoogroups.com <mailto:Doepfer_a100@yahoogroups.com>> 
> wrote:
>
>> Hi there.
>>
>> I am wondering what type of envelope is used on the A-141-2 ADSR. 
>> There is no manual on the doepfer website, but the earlier A-141 has 
>> a manual and the envelope looks to have a 'convex' attack slope and a 
>> 'concave' decay and release.
>>
>>
>> Even though this is a common envelope type, I find it quite strange 
>> that it is not linear. It would then be easy to change from linear to 
>> convex to concave for each section of the envelope by using the CV 
>> inputs. Can somebody veryify if this ADSR is indeed linear or does it 
>> follow the style shown in the A-141 manual.
>>
>> It would be a shame if it's not linear as there really don't seem to 
>> be many CV controlled envelopes out there.
>>
>
>
>