If you want, you can set the filter to re-trigger for every note you play by flipping parameter 46 (trigger). I like the non-retriggering filter, though. It lets me play legato melodies with filter sweeps without having to turn the cutoff knob manually and do sounds almost but not entirely unlike Hammond's percussive sounds.
Those who have actually seen a Poly-800 may now ask "what knob?". The synthetizer's biggest problem is that it, as it came from the factory, does not have anything that resembles real-time control. Fortunately, for cutoff and resonance controls there is a quick and easy fix that makes the instrument much more flexible. On the synth's main circuit board there are some potentiometers, of which VR2 is used to trim filter cutoff and VR5 to trim filter resonance. You can remove them and connect their slots to potentiometers installed on synthetizer's case.
There are rumours that Depeche Mode has used a Poly-800. Jimi Tenor has also owned one.