state variable filter program?

1 post / 0 new
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I have a state variable filter program that gives hi pass, band pass, and lo pass outputs. There are several explanations of how it works, and attributions to Chamberlin, and it looks like it works as advertised, except the hi pass and lo pass outputs are swapped. Without exception, EVERY schematic of a state variable filter shows 3 opamps... the one on the left is a summer and gives the hi pass out, the next stage is an integrator and provides the band pass out, and the third integrator is the lo pass out. The amplitude of the lo pass output ought to be the same as the input at lo freqs, and roll off above the filter freq. But the hi pass out shows this behavior, and the lo pass out shows hi pass response. I dont know why this is. Anyone want to run my program and see if you can see a stupid mistake? OK, now I've attached the kludgey work in progress. Just use menu item 7, not 8.


Imagecraft compiler user