It looks like the matrix for ETMY violin mode5 (508.22 Hz)had its matrix changed on July 17th to actuate on length instead of pitch.  Ed tells me operators have had difficulty damping this mode recently.  I tried switching the matrix back to pitch and have been able to slowly damp the mode using a positive gain and no phase shift.

Keita and I have again changed the matrix back to actuating length, we are now using a gain of positive 20 and +60 degrees for damping, but progress is very slow