Doepfer

I am having a problem with my Dark Energy that is similar to a message that was posted several months earlier, although that message didn't seem to be resolved.  My problem is that whenever I use my DE to process an external signal I am unable to completely disable the oscillator.  I have it to the point where it is almost totally silent but it is still very faintly audible.
I have the PW turned to 0 and the switch to off just as the manual describes.  In the filter section I am noticing that the oscillator sound is most audible when the Frequ. knob is turned around 3.  All of the rest of the filter knobs are set to 0.  I do notice that if I turn the LFM knob up the sound gets louder, but even at 0 it is still there.
I appreciate any advice about this problem since it does interfere when I am processing sounds that have silent parts in them.

Thanks!