Korg Poly 800 with filter-control-knobs

YouTube via moogfreak. I'm guessing this is the MOOG Slayer Mod.
"Hello. In this video I will show you my selfmodified Korg Poly 800. I have added two knobs for filter-control - one for the cutoff and the other one for the resonance. On the back of the synth you can see a switch, which activates the new knobs. In this video you can see and most important hear how it works. The sequence in the beginning and at the end I have programmed on the Poly 800`s build-in sequencer. In the middle I`ve tried to play "Emerson, Lake & Palmer`s" "Aquatarkus", which Keith Emerson has played on his large Moog Modular. For this sound you need three oscillators per note, so I have done this with the Poly 800`s "chord memory"-function. As you can hear - it works very well. But I`m not as good as Keith. :-) Please excuse the pumping compressor/limiter from my videocam."