MOTM

first off, thanks juergen.  awesome email - just what i was looking 
for.

> It's clear that most of the CS-synths' "warmth" comes from its VCOs.
> (I just wanted to state that before I go on to filtering.)

good point.  the tone of the 60 by itself is pretty different (at 
least to my ears) than something passed through its filters.  

> Now what is IMO special about the CS-60 filters ?
>
> (1) Limited Resonance Range

i think this is true, but i don't know, it seems like more than 
that.  it's the quality of what resonance there is that seems to 
stick out for me.  and that's the thing, because the filter sound 
doesn't stand out to me, until you max out the resonance.  

granted, i have no experience with a SEM style filter like what's 
forthcoming from you guys so i couldn't speak to it's sound.  does it 
also share this kinda of dry "seventies" (sorry, lack of a better 
word) sounding resonance?  i have a good idea what the vactrol sound 
is, and it's not like that - not that it lacks body, but it's a more 
high range body.  the vactrol sounds more midrange to me.  and i 
don't have an MS20 (or an MOTM 420) but my frostwave ms20 filter 
clone has a much sharper sound then both the vactrol and the cs60, 
the resonance is the most piercing of the three.

> (2) Limited parameters for the HPF / LPF pair. 
...
> This can hardly happen on a CS-60. Which is better ? Both options
> have their benefits. The Korg MS-20 is a prominent example for the
> other option. (no SV filters here, but a resonant HPF / LPF pair, 
too)

yes, full agreement here, based on my experience with the above 
mentioned frostwave.  the cs-60 is so much less squirelly.  

> (3) The 3rd VCF in the CS-60.

i don't have an expression pedal so i can't speak to this.  

> Bottom Line:
> I really think you can emulate the CS-60 VCF with a pair
> of these forthcoming MOTM SEM-style filters, by just
> using the same CV (and same CV attenuation) for modulation
> inputs, and by keeping the discipline to limit the resonance
> range below a certain position.

i'm eager to hear the new filter.  i'm sure it'll make a welcome 
addition to the rack, cs60 sounding or not. :)  

but tell me if i'm talking out my ass on all this...

alex