Hy there! ![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
I inserted this article some time ago in electronics repair section, but nobody answered. So I hope you will help me here....
I have some old parts of the music center (Panasonic SA-AK45) laying around, and I thought if it's possible from these components to create an audio amplifier, so that I can input some audio signal from computer direct to amplifier, and then output to speakers.
I connected transformer with power circuit. It seemed that transformer is working properly, but when measuring voltage on the main chip, there was nothing. Then I shorted out transistor Q505, which drove the relay. And then on the main chip appeared some voltages. After that I tried to input audio signal from computer to the Left and Right channel. Adding some little test speakers I could hear same signals, but the signal was about as strong as the computer gives, there was no amplification. So I don't know what to do next, perhaps there's still some control signals, or maybe there ir some kind of stand by mode. I would like to ask for your help. I added schematics of power circuit, and I have full user guide, so if you need more information - just ask. Thank you!![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![569400-page-001.jpg 569400-page-001.jpg](https://maker.pro/forums/data/attachments/13/13487-4ca796a5fd0851893ac4f0a6f233900e.jpg)
I inserted this article some time ago in electronics repair section, but nobody answered. So I hope you will help me here....
I have some old parts of the music center (Panasonic SA-AK45) laying around, and I thought if it's possible from these components to create an audio amplifier, so that I can input some audio signal from computer direct to amplifier, and then output to speakers.
I connected transformer with power circuit. It seemed that transformer is working properly, but when measuring voltage on the main chip, there was nothing. Then I shorted out transistor Q505, which drove the relay. And then on the main chip appeared some voltages. After that I tried to input audio signal from computer to the Left and Right channel. Adding some little test speakers I could hear same signals, but the signal was about as strong as the computer gives, there was no amplification. So I don't know what to do next, perhaps there's still some control signals, or maybe there ir some kind of stand by mode. I would like to ask for your help. I added schematics of power circuit, and I have full user guide, so if you need more information - just ask. Thank you!
![569400-page-001.jpg 569400-page-001.jpg](https://maker.pro/forums/data/attachments/13/13487-4ca796a5fd0851893ac4f0a6f233900e.jpg)