Hello Dr. Ear !
perfect sub for 2SA999 are :
- 2SA1783 SANYO
- 2SA1015 TOSHIBA
- 2SA991 NEC
- 2SA673A HITACHI
- 2SA1127 MATSUSHITA
- 2SA933 ROHM
I will choose 2SA1015 easy to find in original !
KSA1015 is a 2SA1015 manufactured today but by FAIRCHILD