Here I am selling rare to find genuine Sony small signal transistor 2SC1364 used as BIAS transistor in Sansui amplifiers AU20000 and BA3000 (version when the BIAS transistor is located on heat-sunk of power stage, not on heat sink of driver transistors). It is very important transistor for proper functioning of the amplifier. Today production of small signal transistors has smaller TO-92 Case Style which can be a problem for proper working BIAS transistor, because that transistor should be mechanical connected with heat-sink of power stage! On the picture #02 and picture #03 you can see how much they are different is size and on picture #05 you can see what I did to get a good mechanical contact with heat-sink.
In the most cases those BIAS transistors  has corrosion because of age (picture #04), and sometime that corrosion could enter into case of transistor, and then you can expect problems, so they should be changed by new ones.

Another problem with new production of small signal transistors could be oscillating! Please take a look to the next you-tube video:
https://youtu.be/Qa1CiursXig

when I changed 2SC1815GR with 2SC1364, the problem gone! With 2SC1364 I didn’t have oscillating, and the power amplifier worked as it should!

2SC1364 what I am selling here I have bought long time ago from Japan seller, and it is genuine Sony.