[sdiy] new CGS filter

[R. Drake]

all,

happened to note that ken stone has recently added a new filter to his
selection of wonderous designs:

> http://www.cgs.synth.net/modules/cgs57_bintic.html
>
> CGS57 -- Bi-N-Tic Filter
>
> This is a strange mixture of a VCO and a switched capacitor filter based on
> the filter presented by Jan Hall in Electronotes. If you are after something
> different, this fits the bill. After all, how many filters have a sync input?
> 
> This filter is based on the original idea by Jan Hall, as presented in
> Electronotes EN92 P14-15, which was in turn based on an idea in a 1974 issue
> of Electronic Design on a Biquart (twice the order) filter.

probably early yet to ask if anyone has built ken's version, but i wonder if
any of you esteemed long-timers had any experience with the original jan
hall design?  or thoughts on the ken's implementation.  comb filter?
ringing bursts?  mmmm...

also noted there are still 4 modules "missing" from the list, assuming
sequential numbering... i kind of like the mystery.  anyone care to guess
what might be in the cooker?

bbob