• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Sansui AU 20000 restoration - many... many pictures

vigman said:
Kale... you had something to share.....?
Click to expand...

Yes... yes... I know... but I really need some free time to do this, because I have some different model of AU20000, with some different preamp boards as on usual model. I hope that I will take some pictures in the next few days, and show you that interesting detail. Once again sorry for delay.
 
Kale said:
Mark, I have worked on that amp about 3 months, but with brakes when had to go to my duty, so I cant tell you how much time I spent working just only on that amp.
About contact cleaner, I am not using just only one liquid for cleaning those units, I have three types of contact cleaners plus two types of thinner.
Click to expand...

What is the steps used to clean the boards so clean? What is the best way to remove old glue and flux? And what are the two types of thinners you use? What type of liquid do you use in the ultrasonic cleaner?

are the videos below similar to what you do?
http://www.youtube.com/watch?v=YB-Ty-_ipi4
http://www.youtube.com/watch?v=dX7ZjtTVj7A

Appreciate any detailed insight as I am learning to restore some vintage Sansui that I have.
 
TranCanCook said:
What is the steps used to clean the boards so clean? What is the best way to remove old glue and flux? And what are the two types of thinners you use?
Click to expand...

For cleaning of electronic circuit board (printed circuit side) I am using Nitro thinner (I dont know the right name on English but I think that is lacquer thinner) , that thinner is also good for removing old glue. Do not use oil-based thinner, oil-based thinner is good sometime when you need to clean some parts which have plastic, because Nitro thinner is very aggressive to plastic parts (like acetone).
For cleaning element side of electronic board I am using isopropanol.

Kontact Kemie I am using for cleaning contact on switches, potentiometers, selectors... (Kontakt WL - degreasing, Kontakt 61 protection already cleaned contacts , Kontakt 60 - deoxidation)

One more thing... I dont like put the complete electronic board into ultrasonic cleaner, ultrasonic cleaner I am using to clean for example wafers of selectors or similar things...
 
Last edited:
Hello Kale,
I have a question, the 3 position attenuation switch to the left of the volume control..
on a CA-3000 (similar to AU 20K ).
The last 3 mm of the switch arm is broken. Have any insight on a slick repair using a similar mechanism ?
Thanks
Mike
 
vigman said:
Hello Kale,
I have a question, the 3 position attenuation switch to the left of the volume control..
on a CA-3000 (similar to AU 20K ).
The last 3 mm of the switch arm is broken. Have any insight on a slick repair using a similar mechanism ?
Thanks
Mike
Click to expand...

Hi, I am not sure what you are trying to ask me... but if you wish just replace switch arm, then you should remove rivet by which the arm is fixed to housing of the switch...

PICT0329.jpg
 
Kale said:
No.. it is not made by teflon, I bought that nylon tube somewhere on internet two, three years ago, but I lost original email, so really I dont remember where... but look at the next web link
http://www.audiokarma.org/forums/showpost.php?p=7326100&postcount=24 member _mano have 2 meters what I sent to him, and he did some searching about the same topic, so I hope he will say something about that...

And about difference between zip ties and nylon tube, I think that Sansui used nylon tubes because it is soft way to keep cables together, so it is not because nylon tube is cheaper, in my opinion it is better way.
Click to expand...

I did use up the 2 meters that was sent, also I was able to get something similar from Australia, 80meters of it, slightly bigger in diameter but does the job. Unfortunately, there will be a fair amount of waste due to fat fingers not nimble enough to do tiny knots. Typically lacing or clove-hitch knots. Could not find anything similar here in UK, similar but rigid tubing is available from fishing tackle shops called as liners, very expensive per meter and found it too rigid.
If Vigman PM me your address, I will post some to you. The Australian craft works website is http://www.miyartcrafts.com.au/Plastic-Lacing.html . I also have access to wax lacing, but wanted to maintain the originality once all completed. Here is a snapshot of the tubing used while I was putting the amp back together.
 

Attachments

  • lacing.jpg
    lacing.jpg
    80.9 KB · Views: 40
Last edited:
Kale,
You wouldn't happen to have that switch arm ? What I'm going to attempt. is to graft ( single splint ) with a new front bit of lever... on mine the last 4mm was broke off, but the switch still functions properly... I cannot find a switch or even a similar one just to get the mechanical bit's out of... I know I have to watch the thickness of the graft, and where I make the graft...Pictures later today
 
Hi I'm working on one of these AU20000, i have rebuilt both F-2507 boards, but I'm having trouble adjusting bias 35mv, it keeps drifting down i reajust it and 20 mins later its 26v.. all my incoming voltages look good, could this be leaky outputs ? any help on this would be fantastic
 
Chris Reed said:
Hi I'm working on one of these AU20000, i have rebuilt both F-2507 boards, but I'm having trouble adjusting bias 35mv, it keeps drifting down i reajust it and 20 mins later its 26v.. all my incoming voltages look good, could this be leaky outputs ? any help on this would be fantastic
Click to expand...
Check BIAS transistor (is it on heat-sink of power stage or on heat-sink of driver board?), and it should have a good thermal contact...
 
MannyE said:
That's not the problem. It's the formerly free service going from 0 to $400 a year without telling anyone they were going to do it.
Click to expand...
It doesn't seem like you know that the Chrome add-on fixes the issue (at least, last time I checked), They will plug the 'hole' eventually - but in the meantime use Chrome and install the add-on - issue fixed! (I believe other browsers are also supported - with the correct add-on for the browser in question).
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom