Does it make a type of whine that coincides with the vibration?  My 1066 does that every so often with the ripper on it and as others have said it's the draft making adjustments.  I finally set the gauge wheels about 2 inches above about where i want to run and just let it all the way down and let it ride.  I figure between tire squat and them pressing into the soil a little, 2 inches is a good guess.