hi all ,
first time to post here.have some problem with amp and hope you guys can give me some advice .
i have a blew 2sa1494 and 2sc3858.i can't get the same at my town .the shopper tell me that 2sa1216 and 2sc2922 will be the same . after solder all the part,it looks and works fine.but it gets fairy hot very fast . i have no idea what's wrong and hope someone can help me it this .Thanks!!!
first time to post here.have some problem with amp and hope you guys can give me some advice .
i have a blew 2sa1494 and 2sc3858.i can't get the same at my town .the shopper tell me that 2sa1216 and 2sc2922 will be the same . after solder all the part,it looks and works fine.but it gets fairy hot very fast . i have no idea what's wrong and hope someone can help me it this .Thanks!!!
Hi,
you probably have not checked and adjusted the output bias current.
If Vbe of the new devices is just slightly lower than the original devices then the output passes a lot more current and this results in much higher power dissipation and heatsink temperatures.
You need to find the set up instructions for the output stage and adjust to the correct values.
Don't use this modified/repaired amplifier until this is attended to properly.
you probably have not checked and adjusted the output bias current.
If Vbe of the new devices is just slightly lower than the original devices then the output passes a lot more current and this results in much higher power dissipation and heatsink temperatures.
You need to find the set up instructions for the output stage and adjust to the correct values.
Don't use this modified/repaired amplifier until this is attended to properly.
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