They had great potential but, since they only worked on 4/1 and needed about two weeks of break-in, it was never realized.
LIRPA1
Does anyone remember the LIRPA1 cartridge? The computer controlled cartridge moved around the record on a small "trailer" that was towed by a tiny, radio controlled car. The information from the grooves was transmitted via FM directly to one's phono stage. Turntable rumble was totally eliminated as was the turntable itself. One only needed a record mat. Whatever became of this great cartridge? More information on this and other LIRPA products may be found in the "Audio" magazine annual buyer's guide that was published every October.