[sdiy] Design for a very strong filter?

[Robert Lorentz]

Hello,

I feel that my studio is in great need of some very very strong LP and
HP filters (and BP would be nice, but less essential).  I am ok as far
as "musical" filters go in order to achieve interesting timbres.
However, I'm looking for filters that would be adjustable cutoff and
extremely strong, like 60db or even higher

The idea here is that I'd be using it for synth patches for specific
spectrum restriction of the instrument, and I logically see that as
being separate from doing eq mixdown on my board.  Plus my board's
eq's are not sweepable anyway


What design is best for this sort of thing?  Looking around it seems
like I need a high order filter (like 10th order), and that it
probably has to be active since I require a tweakable cutoff (unless I
can find a 10ganged pot....)


Precise frequencies and even linearity aren't important here, and
accepting CV isn't required or anything like that.  A main goal is
simplicity though, as I'd like to build a bank of these but have a
relatively small budget for it.


Thanks,

Robert