Does anyone have schematic of this amp?
I have done some repairing (the output transistors were dead), and after music test (party)on JBL TR125 pair speakers the amplifier goes dead again. The ouput transistors and driver 33 Ohms resistors (they set Vbe of the output transistors)
I suspect that amplifier was oscilating.
It has Sziklai doubled output stage.
Original opuput transistors were 2SC4468/2SA1695.
because I couldn't find them I have replaced with 2SC3182/2SA1265.
It has no ouput inductor, only serial network of resistor and capacitor, also has strange parallel capacitor on the output posts.
Please help
I have done some repairing (the output transistors were dead), and after music test (party)on JBL TR125 pair speakers the amplifier goes dead again. The ouput transistors and driver 33 Ohms resistors (they set Vbe of the output transistors)
I suspect that amplifier was oscilating.
It has Sziklai doubled output stage.
Original opuput transistors were 2SC4468/2SA1695.
because I couldn't find them I have replaced with 2SC3182/2SA1265.
It has no ouput inductor, only serial network of resistor and capacitor, also has strange parallel capacitor on the output posts.
Please help
Thanks Leolabs
I have found service manual on www.denom.com linked from the site you have appointed.
I intend using osciloscope for monitoring output and discover if there are any oscilations.
I'll send the schematic as soon as possible. You can suggest some changes
Regards
I have found service manual on www.denom.com linked from the site you have appointed.
I intend using osciloscope for monitoring output and discover if there are any oscilations.
I'll send the schematic as soon as possible. You can suggest some changes
Regards
fake transistors
hi guys
Have you ever heard of fake transistors?
Well that was the second problem with my Onkyo.
I have tried everything but without any result -i was losing my fate in beliving that i could ever repair this amp, and i was succesful with so many others, and then on the internet I spot the column on the esp pages-rod eliot site about counterfeit (fake) transistors.
So i decide to open one of the blown transistors. And I was suprised or i shouldn't be?!!!...the silicon chip of the 2SA1265 (140V, 10A, 100W) Toshiba marked!!?))), is less 3 mm squere??!!, exactly like those pictures in the column.
The other transistor (2SC3182) chip is 5 mm squere-but I think it is also fake. I will put them on test.
So...be aware!, not only the well known transistors could be fake
Vladimir
hi guys
Have you ever heard of fake transistors?
Well that was the second problem with my Onkyo.
I have tried everything but without any result -i was losing my fate in beliving that i could ever repair this amp, and i was succesful with so many others, and then on the internet I spot the column on the esp pages-rod eliot site about counterfeit (fake) transistors.
So i decide to open one of the blown transistors. And I was suprised or i shouldn't be?!!!...the silicon chip of the 2SA1265 (140V, 10A, 100W) Toshiba marked!!?
))), is less 3 mm squere??!!, exactly like those pictures in the column.The other transistor (2SC3182) chip is 5 mm squere-but I think it is also fake. I will put them on test.
So...be aware!, not only the well known transistors could be fake
Vladimir
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