The Sony base is very sturdy, due to a heavy steel plate at the bottom. The steel pylon that attaches to the bottom of the TV set, at right, is discarded.

A little work with a dremel tool opens up the top edge to accept a 1.5" schedule 40 PVC pipe fitting.

I drilled about 15 holes around the bottom edge and permanently attached it to the steel plate with PC-7 epoxy paste.

Then, the trim piece is snapped in place, and fixed by its screw into the bottom plate.

I drilled a .5" hole horizontally into the bottom of the fitting to pass the light tree cable.

You can cement in a pylon starting at 1.5" at the bottom, reducing to 1.25" in the middle, and reducing to 1" at the top to mate with the light tree.