YES! There were TWO versions of the 4-Pole: The more rare to find 9 Volt 'A/C' was Curtis type filter.wald wrote:There is.EvilDragon wrote:There isn't, AFAIK.
The other and one I own is the 12 Volt 'D/C', which is indeed the 'Pulse Filter', which is based upon the Moog Ladder Filter. The audio input was designed by Stefan to use 'any audio as trigger' but he based his design using a bass guitar as the 'typical use'...the trigger input can be anything, just as the mono audio input can be anything...but has a dual stereo output and incredible midi specs.