[Herald1360]

If you can find a suitable stereo cartridge, then yes. You'll need to thread another pair (or at least one) of fine wires down the tonearm and bring the signal out on a suitable connector. You may want to do clever things with switched sockets or flying leads as per the typical OEM add on setups. Ideally the add on amp should be an electrical match for the existing amp and as close to the original speaker layout and box appearance as possible for aesthetic compatibility. Of course more or less any old second channel setup will still give you stereo of a sort.