Doepfer

hello joost,


--- In Doepfer_a100@yahoogroups.com, "levka0" <levka@w...> wrote:
> Hi Ingo
> Thanks for this info
> I have heard the term "sallen & key" before, but I have no idea 
about 
> it's specific meaning. I also heard that the MS20 filter is also 
> a "sallen & key", but this problably has transistors instead of 
> diodes ?

right, the ms20 is also sallen&key, but with transistors.
i don't know what it is that makes sallen&key filters so special,
but i can remember that in sallen&key filters the input/output
levels and cutoff/resonance settings are not independent
from each other. looking at a self-oscillating ms20 filter
on an oscilloscope, it shows very unlinear behaviour and
everything but a clean sinewave. and the filter is really loud
at high resonance settings. maybe this is a bit typical
for sallen&key type filters? anyone having more infos?


> With all the current excitement (also shared by by myself) about 
the 
> most recent cadidate modules (MS50 filt + complex VCO), I suppose 
> that a new filter module for a rather obsure module such as a 
> 700/770/800dv, is presently not very relevant. Maybe some day ....


i'm also very excited about the complex vco suggestion.
ok, we can't have enough filters as they are all different,
but a new oscillator would really make me happy :-)


> just listen at the 800dv mp3's at www.amazona.de for the 
> typical "old" Korg sound for your enjoyment ..


thanks for the link, i'll check it out.

best wishes

ingo