On 5.Aug 2017, at 7:47 , Andrew Simper <andy at cytomic.com> wrote: > I've never got my hands on an actual 904B, nor built/breadboarded one myself, but I have done a dsp model of one and it does sound very cool. > The cutoff is modulated upwards when driven, what do you mean by that? > which to me sound really good for a high pass filter. m.