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I tested transistor Q5 out of circuit. I know, I can't test them inside of it. I will see. If amplifier will work and if one day woun't work anymore, I will simply rechange components that are now life shorted probably. PS.: Can you please check my PCB and tell me if it's good with original schematic?

C13 is good. I made a conuctivity test betwen + and -. It conducts for 1 second, then capacitor is unconductable for few seconds. I think, that Q5 is ok, becouse it conducts between collector and emmitor. It also show resistance between Base and Emitor of about 600 Ohms and in other direction is about 2kOhms. Is That ok? I haven't check other transistors yet..

Which components are in danger thoug?

Can anyone just tell me please, how do I check NPN and PNP transistor with multimeter with range for testing diodes or with ohmmeter without any testing circout?

Yes. I know that. I just didn't look good and now I understand it all. I have transformer with 24V secundary and I connected it's another secondary, so I got 48V. But I was wrong and now I will use original patent of this transformer. At least I know what was wrong now. As they say, we learn on mistakes and I learned something new today. :) Thank you all for your help. I will report on my project on monday, when I get new transistors.

Yes, I followed the instrucions, but I am afraid you're wrong about the transformer. The schematic I made is similar to original one, just that I used rectifier bridge and 48V transformer. If I understood you right, I used too high input voltage ??? Why I should reduce it to 24V?

I don't have transformer with 3 contacts and I used 2 way one. Can anyone check, if schematic is correct? I have tryed circuit, but I didn't connect the speaker and one of the transistors died becouse of the too big current through it. I am now waiting for new trasistor to try my PCB.

yes yes, there are uF. It is logic. Here is my schematic and PCB: amp_fill.pdf amp_fill_layout.pdf amp_fill_shema.pdf

What is strange? ??? There are capacitors from 1 to 13..

Greetings, Did anyone bulid this project already? Can you tell me your experience. And if someone made PCB, can he past it here. I will past mine.. Thank you

Hello, I have build this power supply long time ago, and it didn't work correct. U2 was overheating and output voltage of supply was just 25V. I have changed opamps with OPA455 and now works the same. I have checked every connection, every transistor and diode. Everything is correct. Can you please help me. Now, I know you will say, there is a update of this project on forum and new partslist and all this. But my friend has build it with original schematics and parts list and it works well for him. Can you explain me that please ? Sorry for my bad english