Sanui AU-Alpha907 Limited - IN DA HOUSE!!!

That's such a shame. Service manuals are available for most of the earlier alpha models, but just not the later stuff. Given that Sansui no longer exist (apart from being a 'brand name for sale' for whitegoods and cheap electronic devices) I can't begin to fathom why they would not want this information shared with enthusiasts to help keep these lovely amps working in tip-top condition. By requesting this, they are effectively consigning many amps to the scrap-heap in future (or, at the very least, making life VERY difficult and complex for technicians).
Any chance of obtaining a copy of 907 ltd manual as mine has one channel running far hotter than the other? Will be in Sydney next week and would like to meet up with your father as I missed him last year.
Regards, Alan
 
Any chance of obtaining a copy of 907 ltd manual as mine has one channel running far hotter than the other? Will be in Sydney next week and would like to meet up with your father as I missed him last year.
Regards, Alan

czubsi is the member you should look for asking help on the AU-x907Ltd. Don't ask for manual, just guidance. The manual is rare.
 
hello friends, just a small update about my 907 MOS limited, as i mentioned in my initial post I have cracking noise from one of the channels and fortunately I figured out the problem. I soldered small piece of wire between speaker output relay contacts and noise is gone. Actually this is quite dangerous as I bypassed the protection board. During 2 months testing period with bypass across the relay i realized that noise problem fully gone, and yesterday I removed the bypass and noise returned back. So looks like i need to clean the relay contacts. Any thought about this? may be i missed something and need to check something else in parallel as i'm going to open the protection board.

hope my experience will help

regarding the bias current - its still around 25-27mV and output transistors temperature is about 45-47C which is high but tolerable

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So looks like i need to clean the relay contacts. Any thought about this?

You may get a very temporary improvement by cleaning the relay contacts, but my experience with speaker relays is that once they behave as you describe, the proper action is to replace it/them.
 
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You may get a very temporary improvement by cleaning the relay contacts, but my experience with speaker relays is that once they behave as you describe, the proper action is to replace it/them.

Replace the relays, cleaning the contacts is a complete waste of time.
Just slip a new relay in and you'll be good for another 30 years...

Yes. Replacing the relay is the way to go.

I would consider putting some fresh thermal paste on those outputs too. BUT ... that's just my habit of overkill.
 
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