Here's a great one from my archived Modular2 tips:
<i>
The stepping is not caused by the filter but by the knob that controls the
frequency. So to get rid of it you can use this approach:
use the 'constant val' module instead of the filter knob and route it
through a 6db lowpass filter and into one of the 24 dB filters CFm inputs..
This will smoothen out the sweeps when you move the cutoff knob.. you'll
have to tweak the 6db filter to get the feel you want but the range you
probably should be testing is about 2 or 3 pixels from the minimum...
</i><div align=right>-Claes from Pulsar-Scope