After I plugged the ESP6 into my receiver to make sure both channels were working, I opened it up and took out the disintegrating foam. Which was actually in better condition than the ESP10 foam, this time the foam looked fine until you touched it and chunks broke off. None of it "oozed" onto the PCB/components. The ESP6 and ESP10 share the fact that for some reason Koss really didn't like to use solder and so they have little posts for all the wires which are held in by "locking in." The ESP10 had the wires crimped to washers which were held into the posts by hex nuts. The PCBs are held in with posts/hex nuts. Pretty funny stuff.