I can't seem to figure this one out. My 1/4 in. patchbay starts a high pitch squeal as soon as I patch a good number of things or particular pieces, as I've determined, and that's as much as I can figure out. For instance, I can have 6 patches made, with no squeal. Then I patch in my Yamaha Motif keyboard and what emerges is the worst high pitch squeal. If I take out the Motif, make a couple other patches, I can still have the squeal, but perhaps not as intense. It's soft enough to work for a little while, but loud enough to prevent you from tracking anything important, plus downright annoying. So what I think I know is it's not one piece of gear that keeps getting repatched. Could it be the patchbay itself? Or could there be a half-unplugged connection somewhere? I'm hoping someones else has experienced this sort of thing before.