Q-deck has the same plinth as an Icon. It is like Alec says: you cannot adjust them.
There is an Issue wich counts for the plinth for as well Q-deck and Icon: The felt on the rubber feet and/or the rubber feet themselves 'cave in' (I hope it is the correct English) during time so seriously that the plastic bottom of the Plinth touches the surface on wich the TT stands. Consequence: Increase of Acoustic Feedback. Cure: place between the metal holders of the rubber feet and the MDF Plinth a couple of large format Washers.