Wiardgroup

I have to agree with Olivier - the Omni is quite a useful filter - I
have a first generation "The Filter" and the last version of "The
Super Omni" - after several months of use, it became obvious that the
Super was quite a performer, with many features, such as an adjustable
"constant Q' circuit, which was designed to control the issue of the
filter being more susceptible to oscillatiion at higher frequencies
was also noticably quieter.  It is the fastest of the Wiard filters
(the Boogie being the next fastest, followed by the Borg).  The
bandpass is quite narrow, so Grant has changed the input resistors to
provide a bit of input gain to compensated for lower output of the
bandpass.  What I like about the Omni is how hifi it is - then you can
 drive the input a bit and get whatever amount of grnnge you want.

As Oliver described in his note, the MXR-type phasing produced by the
notch is great - the direct input can be summed to the output, and the
ouput of the filter has a phase switch, so there is plenty of control
to make the filter sound good.

Though Grant has moved on from this design to his voctrol-based
designs, I would feel that something would be missing without the
Omni.  It is the Wiard Filter that can make great articulate bass
patches; while being less "phat" than the Boogie, it's speed makes it
a great filter for many bass applications.

gary