Actually, it’s an interesting filter. BTW, if you transpose Chamberlin’s SVF, you get a similar filter with HP/BP/LP inputs and a common output:
Out = HP + f * (BP + Z1) Z1 += BP - Out * q + f * (Z2 + LP - Out) Z2 += LP - Out f: frequency coefficient q: Q factor coefficient Out: output Z1, Z2: state variables HP, BP, LP: filter inputs HNY! Steffan > On 05.01.2015|KW2, at 14:19, Andrew Simper <a...@cytomic.com> wrote: > > Thanks to the ARP engineers for the original circuit and Sam > HOSHUYAMA's great work for outlining the theory and designing a > schematic for an input mixing SVF. > > Sam's articles- > Theory: http://houshu.at.webry.info/200602/article_1.html > Schematic: http://houshu.at.webry.info/201202/article_2.html > > I have taken Sam's design and written a technical paper on > discretizing this form of the SVF. I also took the chance to update > the SKF (Sallen Key Filter) paper to more explicitly deal with input > mixing of different signals, here they are in as similar form as > possible: > > http://cytomic.com/files/dsp/SvfInputMixing.pdf > http://cytomic.com/files/dsp/SkfInputMixing.pdf > > As always all the technical papers I've done can be accessed from this page: > -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp
