We've got Yulong D200 with broken headphones amplifier.
It have class B power amplifier stage on matched pair of MJD243 with negative feedback from output to OP275 inverting input.
Spending some time on reverse-engineering the output stage schematics we came to the following picture. It might be not quite exact and a bit dirty, but it gives a picture of the actual output stage schematics.
I was unable to determine the exact type of transistors in preamp stage, but got its characteristics, by measuring it on working channel.
Q2=Q7=Q9=Q4 are bipolar NPN transistors, which have the following characteristics
Q3=Q6=Q8=Q5 are bipolar PNP transistors, which have the following characteristics
Finaly I ended up by replacing Q2 with BC847B and R84 with 27 Ohm resistor.
http://www.qobuz.com/gb-en/info/hi-res-guide/yulong-sabre-da8ii-solid177720
https://hi-news.ru/audio/obzor-capa-i-usilitelya-dlya-naushnikov-yulong-d200.html