I was wondering if you would be willing to do a kit that would be high and low pass filters. The first knob could be the lo pass filter frequency and the first switch could control on or bypass. The second knob would control the hi pass filter frequency and the second switch would be on or bypass. I think this would be a hug addition to kit catalog and would be an awesome companion to your pre's.
Having a high pass filter kind of like the filter on a 1073 would be AWESOME! I would probably buy 8 of em right away!
Stephen