Velodyne ULD-15 Rebuild

Has anyone out there retrofit a vintage Velodyne ULD-15 with a new non-servo driver and driven it with an up to date single channel amplifier? If so please let me know what really works. Mine is in excellent physical condition, but it needs a rebuild. I have tried to contact the company in NY that fixes ULD-15s but they never respond. Should I just by a new sub and use my ULD-15 as an end table? Thanks in advance for any useable input.