filter waveform question

[Christopher MacDonald]

Hi,

I have built a diode ladder filter and have a question about the output
waveforms I am getting.  I have posted some oscilloscope photos at:

http://www.evenfall.com/diy/dladder.html

I am wondering if anyone might know what is causing a "jump" or
discontinuity near the peak of the waveform when the resonance control
is turned up.  I have spent hours tinkering with the circuit and can't
figure out what is wrong.  Sigh.


Thanks,

-Chris MacDonald