<p>I understand just barely enough about op-amp filters to get myself in trouble.  I looked at the schematic and said, hm... looks like it's in the feedback loop; no, wait, maybe that one's just an dc input blocker or ... wait... no, maybe it is in the feedback path... or... (confusion reigns)  ;-)  Hell, maybe I'll just see if they've got any 4700pF caps in the EE lab at work.
</p>
