FOur Pole Filter Trubbas!!!

[Romeo Fahl]

I've been fighting with this 4 pole filter that is based on an old
Electr*n*tes design.  The original was billed as a 4 pole lowpass
quadrature vco.  The version I built was designed by Gene Stopp.

I built it with 3 scalable CV inputs, 1 scalable linear FM input and two
audio inputs.  The resonance pot has a lot of range, it will go from normal
cutoff to a clean whistle in three quarters of a turn.  With a mix of
modulation sources (two vcos and two analog sequences) I am able to get a
delightful range of buzzy timbre loops by simply tweaking a few pots.

What bothers me is  that it doesn't sound very bassey.   It seems like the
filter should be sweepable into bassier realms.

Do any of you have any suggestions?

A scan of it is here:

http://www.spiritone.com/~8brain/schems/gslpf.gif