HITACHI HT-L72, HTL72 Turntable equipped with MT-72 cartridge

These models have a specializedT4P pmount-like cartridge that contains an "electronic eye" that "sees" the tracks on the record surface so you can select the tracks you want to play. Do not attempt to replace cartridge with any other type, you will lose the "electronics eye" capabilities of the cartridge for which this needle is designed.
See elliptical 7788-DE below for the only upgrade path available for above applications.