octave up/down / organ effect

[scaesic]

i'm really interested in creating an organ effect by using  a 1/2 octave down, and an octave up circuit. This coupled with a low pass filter should come somewhere near an 88800000 registration on the hammond. (1st 2nd and 3rd harmonics). I found the ehx pog which seems to do this particularly well, but i'd be interested in any information in how ehx acheive such a good response with chords and tracking. Is this a case of a digital pedal making extensive use of notch filters to individually process bands?