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Sansui AU 20000 restoration - many... many pictures

Kale,your work is truly an inspiration for all of us :ntwrthy:

Are you sure you don't need an apprentice :D
 
Kale, if a picture is worth a thoasand words you are a master story teller. Thank you for sharing the restoration.
 
I wish I had time to learn this kind of work, it is very interesting to me

thanks for sharing your talent and for preserving these classic pieces that need to live for another generation to experience.
 
DCinDC said:
Haven't read the whole thread yet, but wanted to say to Kale that I have two different reg ps boards here and a couple of AU-20ks that have the output stages soldered on instead of the gold plug in pin assys.
Click to expand...

I have had one BA3000 which has output stage wires soldered on the Motherboard, but until now I didnt see that on some AU20000

DCinDC said:
We also know there are two different output stages, 1 with bias transistor on it, 1 without. Same for the driver boards, where the bias transistor moved from/to.
Click to expand...
The same thing on that BA3000 was with bias transistor
 
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@ DVNOBLE

YOU did great job, all those resistor changed by you is really a big work!

But I have some questions; why you didnt change trimmers on driver board, or as I can see you changed trimmers on one driver board, but with some open type. Those trimmers are so important (BIAS and DC Offset), so it will be the best if you use some multi-turn type.
And as second; why you didnt change those serial diodes with 1N4148 ?
 
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kevzep said:
Nice work Kale, looks like the previous "technician, or butcher" used whatever screws they had lying around to secure one of the output transistors!!

I like the work you do to clean up the circuit boards, dismantle and clean the switches....

I also like those emitter resistors you are using.......
Click to expand...

Thank you!
Those emiter resistors are 12Watt MILLS non-inductive resistors, and I like to use them at Sansui amplifiers - receivers
 
OK, some more pictures....

The Tone Control Board

PICT0408.jpg


Potentiometers ready for cleaning

PICT0409.jpg


is it like new now :)

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PICT0411.jpg
 
Output Selector

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Sansui used two the same wafers for each contact to reduce crossover resistance but it is really hard job to dismount the both wafers to clean them

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you see now about what I was talking above:

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ready for cleaning

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again like a new :)

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and connected back to its place

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And now, Tape Copy Selector... but first you should see this

PICT0448.jpg


this is one unused pin of that selector, but it is bended on wrong way :no:

To dismount that selector, you should remove all small signal cables

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very demanding job...

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finally it is out

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here you can see how it was looking

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the both wafers ready for cleaning

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and like new...

PICT0457.jpg
 
Kale, your work is so astonishing - sometimes it seems like you have brand new replacement parts (PCB's Switches etc) as the clean up job you do is so thorough.

Thanks for posting the story :thmbsp:
 
again cleaning.... cleaning... and again cleaning.....

PICT0466.jpg


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here I have found a problem with Balance pot... it had a bad contact, but it is not simple to dismount it, look at the next picture :

PICT0469.jpg


the axle of potentiometer is nailed, and you should remove just only small part of that, just enough to separate the axle from other part of potentiometer.

Here you can see all parts of Balance potentiometer

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Now it is clear why it had bad contact

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and again reassembled

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and here it is, like a new :)

PICT0476.jpg
 
Man, somebody farked that amp up good. Just a shame what was done to it, and a blessing you ended up with it.

Where you get the NOS outputs?
 
Hyperion said:
Kale, your work is so astonishing - sometimes it seems like you have brand new replacement parts (PCB's Switches etc) as the clean up job you do is so thorough.
Click to expand...
Thank you John... but each day is harder and harder to do like these things, my eyesight is getting worse, so I do not know how long I will doing restorations on Sansuies...
 
Ok... the small signal cables are soldered back to theirs place

PICT0477.jpg


and now light of power meters...

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as you can see, the lam was not like it should be, old lam was 6.3V, but it should be 7 V

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the new correct lamps installed

PICT0490.jpg
 
The story is closer to the end, now I am tired, so I will post the last pictures tomorrow, so... stay tuned :smoke:
 
Hey Kale.........absolutely marvellous job! I was studying your pictures in post #32. On the meter circuit board......how did you orientate the capacitors that were in the wrong way? I noticed that you put 2 caps in the 'wrong' way and 1 cap(C03) in the 'right' way.....how do you know which is correct? The board.....or the cap? Which way do you trust?
GREAT JOB and GREAT STORY!
 
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