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Fix that Sansui 9090db with a Bad db board

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As much as the idea of bypassing the dolby board is easy, I still struggle with the fact that tape input / output doesn't work. Would be great if someone figured out a way to get it so the tape works as well. I still don't find the service for the dolby board that difficult once you learn the easy ways to access and get the board out.
 
This was my way of bypassing the db board.

Duplicate the schematic and solder it all up in point to point fashion aside from the driver board which I replaced with a tolitom board.
 

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CharlieBee said:
Do not throw away your Sansui 9090db with bad Dolby board. AK link below shows how to bypass the Dolby board on a Sansui 9090db receiver.
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LBPete said:
That bypass also bypasses the tape input/output. You won't be able to connect a tape deck after doing it.
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If you ever sell it, you now must inform the buyer that the receiver is no longer 100% functional. This would be no deal for me since I utilize a cassette deck, RTR and CD player in my system.
 
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tarior said:
There is no reason to bypass the Dolby board. Pin and solder the vias and it will work perfectly if you do your part. After you've done a few, it takes about an hour or so.
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More reliable device, cleaner and shorter path for the signal.
 
tarior said:
When repaired properly, that board is perfectly reliable, and the unit retains all of its functionality.
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If they were perfectly reliable when repaired properly then they would be perfectly reliable when assembled properly at the factory. But they are not...
 
z-adamson said:
If they were perfectly reliable when repaired properly then they would be perfectly reliable when assembled properly at the factory. But they are not...
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Logical fallacy much? They had a design flaw, or actually more like an implementation flaw, that is corrected fairly easily. Once corrected, they are perfectly fine. Removing a large portion of the receiver's functionality is not a proper repair, it is a hokey cludge. Repair it properly or leave it to someone who will, IMO.
 
tarior said:
Logical fallacy much? They had a design flaw, or actually more like an implementation flaw, that is corrected fairly easily. Once corrected, they are perfectly fine. Removing a large portion of the receiver's functionality is not a proper repair, it is a hokey cludge. Repair it properly or leave it to someone who will, IMO.
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QRX Restore down in Eugene Oregon bypasses the Dolby board on everything they restore that has one. Why do you suppose that is? And, no functionality loss. It’s useless and it creates problems. Better off without it. The most reputable dedicated Sansui shop out there, and they bypass them all. Maybe you could give them a lesson on how to restore Sansui devices. Perhaps you know something they don’t. Spread the wisdom around.

I got rid of the Dolby Board and more on my 9090db. Much better this way in my opinion.
 
Hipocrates said:
Is a lost battle, I don't remember where this whole bypass thing came out, but is one of those things that internet people repeat and believe with passion.:bs:
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Probably the founder of QRX Restore. He was a fairly prolific poster here until his passing (RIP). The bypass, the diff mod....other things too. He came up with many ways to make these Sansui receivers more reliable and better performing.
 
tarior said:
The appeal to authority thing really has no sway on me. None of the techs whom I respect and learned from would ever make a hokey cludge that removes the tape in/out function and call it an improvement. It's just bad work.
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Lets make one thing clear, their bypass method does not involve removing tape in/out. I said "....And, no functionality loss....".

The ONLY thing bypassed is the DB board.

In light of the above, is it still a hokey kludge that constitutes bad work?

They bypassed the board on my 9090db and I did take pics of it but they got deleted and I no longer have them to share. I wish I could explain and show how they do it, but unfortunately, I can't. I have since modded my 9090db to my taste (see pics above) so photographing my device won't help here either....sigh. But I can tell you it involves jumper wires, it works and the tape in/out still functions.
 
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