Doepfer

Duff,

Sallen-Key filters are 2 pole filters.  Also, using a true Sallen-Key 
filter for bandpass purposes isn't really advised, as the input 
resistor is a very low value, and changing the value also changes the 
overall behavior and characteristics of the filter.

That said, Korg did a very nice job of it, so the whole bandpass 
thing could be argued.

Regards,
Kevin