Recapping AU20000?
How hard is this task? I am going to take a stab at it really soon. Gonna practice on some old junky piece of gear first though. What caps do you guys recommend? Where do i get them? I may as well replace the output transistors as well? I should check the DC offset too. Any suggestions would be greatly appreciated. Flux and solder suggestions? Solder gun? I talked to a tech last week and i told him the AU is severely lacking in bass response and he told me it sounds like it needs to be recapped.Mike
Originally Posted by mfellHow hard is this task?
Quite the chore on this one.What caps do you guys recommend?
Panasonic FM amp; FC and Nichicon PW amp; HE. For non-polar electrolytics, Panasonic SU will do.Where do i get them?
Digikey.
I may as well replace the output transistors as well?
Good God, no. Unless there are blown ones, leave them alone.
I should check the DC offset too.
Duh!
Any suggestions would be greatly appreciated. Flux and solder suggestions?
Kester 44 solder, and Kester flux.
Solder gun?
Depends on what you want to spend.
Agreed,
I completely did all boards in my 9900 and there are alot of screws to pull and alot not to pull...meaning by pulling some you can sneak out the boards well enough to do the recap...but pulling too many will make it fall apart.... moving the beast then becomes precarious!!
Originally Posted by EchoWarsQuite the chore on this one.Panasonic FM amp; FC and Nichicon PW amp; HE. For non-polar electrolytics, Panasonic SU will do.Digikey.Good God, no. Unless there are blown ones, leave them alone.Duh
Well I am not an electronics technician I am just a musician who happens to be craving high fidelity and my problem is the local techs don't want to even work on this thing due to its complexity. I am not going to ship this thing either as i have little faith in any of the shippers allowing this thing to reach its destination in one piece. I had to laugh when the one tech today stated it is not even worth fixing and that parts are impossible to find. I think he was checking to see if i would pawn it off on him. I really appreciate all the helpful information you have provided me here. I know I ask stupid questions at times. This is how I learn. I have learned quite a bit here and no doubt I have a lot of learning ahead of me. Thanks again.
Solder guns are generally too big/powerful for all but the biggest joints IMO. An ordinary 50w soldering iron is all you will need - try to get a temperature controlled one - I favour Weller - but there are several other good makes.
I also don't feel the need for separate flux - as I use flux cored solder, however separate flux can be of use sometimes.
Have a read of the re-capping threads here on AK - you will soon pick up how the minds of the re-capping experts work.
John
Originally Posted by mfell...I am not going to ship this thing either as i have little faith in any of the shippers allowing this thing to reach its destination in one piece. ...
...I really appreciate all the helpful information you have provided me here. I know I ask stupid questions at times. This is how I learn. I have learned quite a bit here and no doubt I have a lot of learning ahead of me. Thanks again.
I've gotten some really good help here on AK, but I've found that what's made me the Sansui technician I am today ( ) is my own research.
Almost all of your yet undiscovered questions have already been asked and answered here on AK so make the quot;Searchquot; function your friend.
I've also found that the ones here who are the most qualified to answer questions can get just a little unforgiving if the question itself indicates that you are simply looking for someone else to do your work for you.
Be willing to tax your brain by following up on your own questions with more research on your own, and when you really need help on the tough questions, you'll find that the pros here will be more than happy to nudge you along in the right direction.
As far as your doing your AU -20000, I really think it's a little more than you might want to tackle as your first amp. I've done several other amps now, and I'm just getting up the courage to dig into my AU-9900A.
Shipping really can be done safely as long as you understand how to pack it, so considering that your AU-20000 represents the TOTL of a TOTL marque, I wish you'd consider having EchoWars or another pro do it for you.
If you still decide to try it yourself, you asked about soldering irons: I had a Xytronic soldering station for a few years that bit the dust recently, so I tossed it and replaced it with a new Weller WD-1002. I never knew that soldering could be so much fun.
What you want is any soldering station around 50watts or more that allows you to set the temperature (and it keeps it there).
EW gave you the basic points, but when you redo these amps, the overview is:
1. Replace ALL electrolytic capacitors (except see point #2). I personally like Nichicon PW for most applications. You generally do not need to replace other types of capacitors... but sometimes, you do. (quot;Searchquot;, and you shall find).
2. I don't replace the main caps if they aren't leaking and the amp sounds good after replacing the rest of the E-caps. Other people do... go figure.
3. Replace any components that have corroded leads or if they show signs of having overheated (darkening under them on the PCB or black leads).
4. Do NOT replace transistors just for the hell of it, especially the output transistors because it's almost impossible to find quot;perfectly originalquot; replacements. If they're good, leave 'em alone.
5. Take lot's of pics of the boards and wiring before, and as, you take it apart. You will need those pics to put it together properly.
There's lot's more, but that's all there is on the tip of my head at the moment.
Good luck.
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