Chinese amp problem

[rrae]

Came amp with totally blown power supply.
Ok, thats not the problem for now, i wonder why the rail capacitors have smaller capacity than its marked on pcb? Another thing is the outputs, they are now 2SB817/2SD1047, same problem - on pcb its marked 2SA1943/2SC5200.
Amp guts - www.LJclub.net
I wonder if 2sa1943/2sc5200 will work, as they are printed on pcb, because they have higher fT than 2sb817, amp uses TIP42/TIP41 as drivers.
Seems like the all parts are "original" manufactured.
2SA1943 - http://www.toshiba.com/taec/components2/Datasheet_Sync/66/7673.pdf
2SB817 - http://www.sm0vpo.com/_pdf/2SB/2SB817.PDF

 

[Perry Babin]

Any of these transistors will probably work.

The FJA4213 and FJA4313 have worked as subs in every Chinese/Korean amp that I've tried them in that use this case style.

 

[rrae]

2SA1943/2SC5200 are higher power than 2SB817/2SD1047, will it be audible, if the power supply stays the same?
You have idea about caps? Why they have 2200uf/50v instead of, like its marked on pcb - 4700uf/50v?

 

[Perry Babin]

Neither will make an audible difference.

The power dissipation by the transistor is a function of the voltage across the collector/emitter and the current passing through the transistor. The maximum power dissipation is generally determined by case style (a larger case can more efficiently transfer heat to the heatsink).

You could probably install 1000uf caps and not tell the difference.

 

[rrae]

Thank You for the answers!
I dont have right now on hand 2SA1015, seems like 2SA1266 should work!? 2SA1015 is for FET driving.
http://www.paco-electronics.com/pdf/2SA1266.pdf
http://phys.thu.edu.tw/~mengwen/exp-electronics/datasheet/2SA1015.pdf

 

[Perry Babin]

Those are interchangeable.