They are stamped with the letter Y, as in Y 1L , or Y 1M.
Also, is there some sort of matching required for the SANKEN A1303/C3284 output transistors in 907 MR. Some of them have 8N P/ 16 P stamped, others 44 Y/ 10 Y.
I followed several very impressive youtube videos of yours, repairing different Sansui amps. I am a total newbie in this field, so please excuse my incompetence on the matter. I wonder if you happen to know what MOS FET Vgs values the output transistors Toshiba 2SK405/2SJ115 have to have for 907i MOS Ltd. Trying to stock up on parts for preventive maintenance.